There was an error saving your invoice

Hi

I just tried to create a recurring invoice for a client both through the client UI and also through the recurring invoice UI but got the following error:

https://prnt.sc/lmof0z

Any thoughts…?

I’d suggest checking the web server error logs for more details.

Here’s what I found…

Not sure if it helps…

refox/63.0"
83.42.134.164 - - [25/Nov/2018:09:16:00 +0000] “GET /fonts/fontawesome-webfont.woff2?v=4.7.0 HTTP/1.1” 200 0 “https://billing.MyDomain.co.uk/css/built.css?no_cache=4.4.2” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:16:00 +0000] “GET /dashboard_chart_data/day/2018-10-27/2018-11-25/2/true HTTP/1.1” 200 338 “https://billing.MyDomain.co.uk/dashboard” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:16:04 +0000] “GET /dashboard HTTP/1.1” 200 33066 “https://billing.MyDomain.co.uk/dashboard” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:16:06 +0000] “GET /dashboard_chart_data/day/2018-10-27/2018-11-25/2/true HTTP/1.1” 200 338 “https://billing.MyDomain.co.uk/dashboard” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:16:06 +0000] “GET /account/get_search_data HTTP/1.1” 200 286836 “https://billing.MyDomain.co.uk/dashboard” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:16:21 +0000] “GET /invoices HTTP/1.1” 200 15824 “https://billing.MyDomain.co.uk/dashboard” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:16:21 +0000] “GET /css/select2.css HTTP/1.1” 200 0 “https://billing.MyDomain.co.uk/invoices” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:16:21 +0000] “GET /api/invoices?sEcho=1&iColumns=9&sColumns=%2C%2C%2C%2C%2C%2C%2C%2C&iDisplayStart=0&iDisplayLength=50&mDataProp_0=0&sSearch_0=&bRegex_0=false&bSearchable_0=true&bSortable_0=false&mDataProp_1=1&sSearch_1=&bRegex_1=false&bSearchable_1=true&bSortable_1=true&mDataProp_2=2&sSearch_2=&bRegex_2=false&bSearchable_2=true&bSortable_2=true&mDataProp_3=3&sSearch_3=&bRegex_3=false&bSearchable_3=true&bSortable_3=true&mDataProp_4=4&sSearch_4=&bRegex_4=false&bSearchable_4=true&bSortable_4=true&mDataProp_5=5&sSearch_5=&bRegex_5=false&bSearchable_5=true&bSortable_5=true&mDataProp_6=6&sSearch_6=&bRegex_6=false&bSearchable_6=true&bSortable_6=true&mDataProp_7=7&sSearch_7=&bRegex_7=false&bSearchable_7=true&bSortable_7=true&mDataProp_8=8&sSearch_8=&bRegex_8=false&bSearchable_8=true&bSortable_8=false&sSearch=&bRegex=false&iSortCol_0=6&sSortDir_0=desc&iSortingCols=1&=1543137384431 HTTP/1.1" 200 76544 “https://billing.MyDomain.co.uk/invoices” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:16:25 +0000] "GET /api/invoices?sEcho=2&iColumns=9&sColumns=%2C%2C%2C%2C%2C%2C%2C%2C&iDisplayStart=0&iDisplayLength=50&mDataProp_0=0&sSearch_0=&bRegex_0=false&bSearchable_0=true&bSortable_0=false&mDataProp_1=1&sSearch_1=&bRegex_1=false&bSearchable_1=true&bSortable_1=true&mDataProp_2=2&sSearch_2=&bRegex_2=false&bSearchable_2=true&bSortable_2=true&mDataProp_3=3&sSearch_3=&bRegex_3=false&bSearchable_3=true&bSortable_3=true&mDataProp_4=4&sSearch_4=&bRegex_4=false&bSearchable_4=true&bSortable_4=true&mDataProp_5=5&sSearch_5=&bRegex_5=false&bSearchable_5=true&bSortable_5=true&mDataProp_6=6&sSearch_6=&bRegex_6=false&bSearchable_6=true&bSortable_6=true&mDataProp_7=7&sSearch_7=&bRegex_7=false&bSearchable_7=true&bSortable_7=true&mDataProp_8=8&sSearch_8=&bRegex_8=false&bSearchable_8=true&bSortable_8=false&sSearch=tenerifescubadiving.co.uk&bRegex=false&iSortCol_0=6&sSortDir_0=desc&iSortingCols=1&
=1543137384432 HTTP/1.1” 200 66 “https://billing.MyDomain.co.uk/invoices” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:16:32 +0000] “GET /clients HTTP/1.1” 200 15651 “https://billing.MyDomain.co.uk/invoices” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:16:32 +0000] “GET /css/cookieconsent.min.css HTTP/1.1” 200 0 “https://billing.MyDomain.co.uk/clients” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:16:33 +0000] “GET /api/clients?sEcho=1&iColumns=8&sColumns=%2C%2C%2C%2C%2C%2C%2C&iDisplayStart=0&iDisplayLength=25&mDataProp_0=0&sSearch_0=&bRegex_0=false&bSearchable_0=true&bSortable_0=false&mDataProp_1=1&sSearch_1=&bRegex_1=false&bSearchable_1=true&bSortable_1=true&mDataProp_2=2&sSearch_2=&bRegex_2=false&bSearchable_2=true&bSortable_2=true&mDataProp_3=3&sSearch_3=&bRegex_3=false&bSearchable_3=true&bSortable_3=true&mDataProp_4=4&sSearch_4=&bRegex_4=false&bSearchable_4=true&bSortable_4=true&mDataProp_5=5&sSearch_5=&bRegex_5=false&bSearchable_5=true&bSortable_5=true&mDataProp_6=6&sSearch_6=&bRegex_6=false&bSearchable_6=true&bSortable_6=true&mDataProp_7=7&sSearch_7=&bRegex_7=false&bSearchable_7=true&bSortable_7=false&sSearch=&bRegex=false&iSortCol_0=6&sSortDir_0=desc&iSortingCols=1&=1543137395669 HTTP/1.1" 200 44416 “https://billing.MyDomain.co.uk/clients” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:16:34 +0000] "GET /api/clients?sEcho=2&iColumns=8&sColumns=%2C%2C%2C%2C%2C%2C%2C&iDisplayStart=0&iDisplayLength=25&mDataProp_0=0&sSearch_0=&bRegex_0=false&bSearchable_0=true&bSortable_0=false&mDataProp_1=1&sSearch_1=&bRegex_1=false&bSearchable_1=true&bSortable_1=true&mDataProp_2=2&sSearch_2=&bRegex_2=false&bSearchable_2=true&bSortable_2=true&mDataProp_3=3&sSearch_3=&bRegex_3=false&bSearchable_3=true&bSortable_3=true&mDataProp_4=4&sSearch_4=&bRegex_4=false&bSearchable_4=true&bSortable_4=true&mDataProp_5=5&sSearch_5=&bRegex_5=false&bSearchable_5=true&bSortable_5=true&mDataProp_6=6&sSearch_6=&bRegex_6=false&bSearchable_6=true&bSortable_6=true&mDataProp_7=7&sSearch_7=&bRegex_7=false&bSearchable_7=true&bSortable_7=false&sSearch=tenerifescubadiving.co.uk&bRegex=false&iSortCol_0=6&sSortDir_0=desc&iSortingCols=1&
=1543137395670 HTTP/1.1” 200 66 “https://billing.MyDomain.co.uk/clients” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:16:37 +0000] “GET /clients HTTP/1.1” 200 15645 “https://billing.MyDomain.co.uk/clients” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:16:37 +0000] “GET /api/clients?sEcho=1&iColumns=8&sColumns=%2C%2C%2C%2C%2C%2C%2C&iDisplayStart=0&iDisplayLength=25&mDataProp_0=0&sSearch_0=&bRegex_0=false&bSearchable_0=true&bSortable_0=false&mDataProp_1=1&sSearch_1=&bRegex_1=false&bSearchable_1=true&bSortable_1=true&mDataProp_2=2&sSearch_2=&bRegex_2=false&bSearchable_2=true&bSortable_2=true&mDataProp_3=3&sSearch_3=&bRegex_3=false&bSearchable_3=true&bSortable_3=true&mDataProp_4=4&sSearch_4=&bRegex_4=false&bSearchable_4=true&bSortable_4=true&mDataProp_5=5&sSearch_5=&bRegex_5=false&bSearchable_5=true&bSortable_5=true&mDataProp_6=6&sSearch_6=&bRegex_6=false&bSearchable_6=true&bSortable_6=true&mDataProp_7=7&sSearch_7=&bRegex_7=false&bSearchable_7=true&bSortable_7=false&sSearch=&bRegex=false&iSortCol_0=6&sSortDir_0=desc&iSortingCols=1&=1543137400287 HTTP/1.1" 200 44416 “https://billing.MyDomain.co.uk/clients” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:16:40 +0000] "GET /api/clients?sEcho=2&iColumns=8&sColumns=%2C%2C%2C%2C%2C%2C%2C&iDisplayStart=0&iDisplayLength=25&mDataProp_0=0&sSearch_0=&bRegex_0=false&bSearchable_0=true&bSortable_0=false&mDataProp_1=1&sSearch_1=&bRegex_1=false&bSearchable_1=true&bSortable_1=true&mDataProp_2=2&sSearch_2=&bRegex_2=false&bSearchable_2=true&bSortable_2=true&mDataProp_3=3&sSearch_3=&bRegex_3=false&bSearchable_3=true&bSortable_3=true&mDataProp_4=4&sSearch_4=&bRegex_4=false&bSearchable_4=true&bSortable_4=true&mDataProp_5=5&sSearch_5=&bRegex_5=false&bSearchable_5=true&bSortable_5=true&mDataProp_6=6&sSearch_6=&bRegex_6=false&bSearchable_6=true&bSortable_6=true&mDataProp_7=7&sSearch_7=&bRegex_7=false&bSearchable_7=true&bSortable_7=false&sSearch=scuba&bRegex=false&iSortCol_0=6&sSortDir_0=desc&iSortingCols=1&
=1543137400288 HTTP/1.1” 200 3569 “https://billing.MyDomain.co.uk/clients” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:16:42 +0000] “GET /clients/2 HTTP/1.1” 200 21812 “https://billing.MyDomain.co.uk/clients” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:22:37 +0000] “GET /clients HTTP/1.1” 200 15639 “https://billing.MyDomain.co.uk/clients/2” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:22:38 +0000] “GET /css/cookieconsent.min.css HTTP/1.1” 200 1029 “https://billing.MyDomain.co.uk/clients” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:22:38 +0000] “GET /css/select2.css HTTP/1.1” 200 0 “https://billing.MyDomain.co.uk/clients” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:22:38 +0000] “GET /api/clients?sEcho=1&iColumns=8&sColumns=%2C%2C%2C%2C%2C%2C%2C&iDisplayStart=0&iDisplayLength=25&mDataProp_0=0&sSearch_0=&bRegex_0=false&bSearchable_0=true&bSortable_0=false&mDataProp_1=1&sSearch_1=&bRegex_1=false&bSearchable_1=true&bSortable_1=true&mDataProp_2=2&sSearch_2=&bRegex_2=false&bSearchable_2=true&bSortable_2=true&mDataProp_3=3&sSearch_3=&bRegex_3=false&bSearchable_3=true&bSortable_3=true&mDataProp_4=4&sSearch_4=&bRegex_4=false&bSearchable_4=true&bSortable_4=true&mDataProp_5=5&sSearch_5=&bRegex_5=false&bSearchable_5=true&bSortable_5=true&mDataProp_6=6&sSearch_6=&bRegex_6=false&bSearchable_6=true&bSortable_6=true&mDataProp_7=7&sSearch_7=&bRegex_7=false&bSearchable_7=true&bSortable_7=false&sSearch=&bRegex=false&iSortCol_0=6&sSortDir_0=desc&iSortingCols=1&=1543137760951 HTTP/1.1" 200 44416 “https://billing.MyDomain.co.uk/clients” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:22:44 +0000] "GET /api/clients?sEcho=2&iColumns=8&sColumns=%2C%2C%2C%2C%2C%2C%2C&iDisplayStart=0&iDisplayLength=25&mDataProp_0=0&sSearch_0=&bRegex_0=false&bSearchable_0=true&bSortable_0=false&mDataProp_1=1&sSearch_1=&bRegex_1=false&bSearchable_1=true&bSortable_1=true&mDataProp_2=2&sSearch_2=&bRegex_2=false&bSearchable_2=true&bSortable_2=true&mDataProp_3=3&sSearch_3=&bRegex_3=false&bSearchable_3=true&bSortable_3=true&mDataProp_4=4&sSearch_4=&bRegex_4=false&bSearchable_4=true&bSortable_4=true&mDataProp_5=5&sSearch_5=&bRegex_5=false&bSearchable_5=true&bSortable_5=true&mDataProp_6=6&sSearch_6=&bRegex_6=false&bSearchable_6=true&bSortable_6=true&mDataProp_7=7&sSearch_7=&bRegex_7=false&bSearchable_7=true&bSortable_7=false&sSearch=autos&bRegex=false&iSortCol_0=6&sSortDir_0=desc&iSortingCols=1&
=1543137760952 HTTP/1.1” 200 1809 “https://billing.MyDomain.co.uk/clients” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:22:46 +0000] “GET /clients/18 HTTP/1.1” 200 20942 “https://billing.MyDomain.co.uk/clients” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:22:46 +0000] “GET /css/cookieconsent.min.css HTTP/1.1” 200 1029 “https://billing.MyDomain.co.uk/clients/18” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:22:46 +0000] “GET /css/select2.css HTTP/1.1” 200 1812 “https://billing.MyDomain.co.uk/clients/18” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:16:43 +0000] “GET /api/recurring_invoices/2?sEcho=1&iColumns=8&sColumns=%2C%2C%2C%2C%2C%2C%2C&iDisplayStart=0&iDisplayLength=10&mDataProp_0=0&sSearch_0=&bRegex_0=false&bSearchable_0=true&bSortable_0=false&mDataProp_1=1&sSearch_1=&bRegex_1=false&bSearchable_1=true&bSortable_1=true&mDataProp_2=2&sSearch_2=&bRegex_2=false&bSearchable_2=true&bSortable_2=true&mDataProp_3=3&sSearch_3=&bRegex_3=false&bSearchable_3=true&bSortable_3=true&mDataProp_4=4&sSearch_4=&bRegex_4=false&bSearchable_4=true&bSortable_4=true&mDataProp_5=5&sSearch_5=&bRegex_5=false&bSearchable_5=true&bSortable_5=true&mDataProp_6=6&sSearch_6=&bRegex_6=false&bSearchable_6=true&bSortable_6=true&mDataProp_7=7&sSearch_7=&bRegex_7=false&bSearchable_7=true&bSortable_7=false&sSearch=&bRegex=false&iSortCol_0=0&sSortDir_0=desc&iSortingCols=1&=1543137405587 HTTP/1.1" 200 9612 “https://billing.MyDomain.co.uk/clients/2” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:22:47 +0000] "GET /api/recurring_invoices/18?sEcho=1&iColumns=8&sColumns=%2C%2C%2C%2C%2C%2C%2C&iDisplayStart=0&iDisplayLength=10&mDataProp_0=0&sSearch_0=&bRegex_0=false&bSearchable_0=true&bSortable_0=false&mDataProp_1=1&sSearch_1=&bRegex_1=false&bSearchable_1=true&bSortable_1=true&mDataProp_2=2&sSearch_2=&bRegex_2=false&bSearchable_2=true&bSortable_2=true&mDataProp_3=3&sSearch_3=&bRegex_3=false&bSearchable_3=true&bSortable_3=true&mDataProp_4=4&sSearch_4=&bRegex_4=false&bSearchable_4=true&bSortable_4=true&mDataProp_5=5&sSearch_5=&bRegex_5=false&bSearchable_5=true&bSortable_5=true&mDataProp_6=6&sSearch_6=&bRegex_6=false&bSearchable_6=true&bSortable_6=true&mDataProp_7=7&sSearch_7=&bRegex_7=false&bSearchable_7=true&bSortable_7=false&sSearch=&bRegex=false&iSortCol_0=0&sSortDir_0=desc&iSortingCols=1&
=1543137769481 HTTP/1.1” 200 4160 “https://billing.MyDomain.co.uk/clients/18” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:36:46 +0000] “GET /clients HTTP/1.1” 200 15597 “https://billing.MyDomain.co.uk/clients/18” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:36:47 +0000] “GET /css/cookieconsent.min.css HTTP/1.1” 200 0 “https://billing.MyDomain.co.uk/clients” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:36:47 +0000] “GET /apple-touch-icon.png HTTP/1.1” 200 0 “-” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:36:47 +0000] “GET /api/clients?sEcho=1&iColumns=8&sColumns=%2C%2C%2C%2C%2C%2C%2C&iDisplayStart=0&iDisplayLength=25&mDataProp_0=0&sSearch_0=&bRegex_0=false&bSearchable_0=true&bSortable_0=false&mDataProp_1=1&sSearch_1=&bRegex_1=false&bSearchable_1=true&bSortable_1=true&mDataProp_2=2&sSearch_2=&bRegex_2=false&bSearchable_2=true&bSortable_2=true&mDataProp_3=3&sSearch_3=&bRegex_3=false&bSearchable_3=true&bSortable_3=true&mDataProp_4=4&sSearch_4=&bRegex_4=false&bSearchable_4=true&bSortable_4=true&mDataProp_5=5&sSearch_5=&bRegex_5=false&bSearchable_5=true&bSortable_5=true&mDataProp_6=6&sSearch_6=&bRegex_6=false&bSearchable_6=true&bSortable_6=true&mDataProp_7=7&sSearch_7=&bRegex_7=false&bSearchable_7=true&bSortable_7=false&sSearch=&bRegex=false&iSortCol_0=6&sSortDir_0=desc&iSortingCols=1&=1543138609684 HTTP/1.1" 200 44416 “https://billing.MyDomain.co.uk/clients” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:36:50 +0000] "GET /api/clients?sEcho=2&iColumns=8&sColumns=%2C%2C%2C%2C%2C%2C%2C&iDisplayStart=0&iDisplayLength=25&mDataProp_0=0&sSearch_0=&bRegex_0=false&bSearchable_0=true&bSortable_0=false&mDataProp_1=1&sSearch_1=&bRegex_1=false&bSearchable_1=true&bSortable_1=true&mDataProp_2=2&sSearch_2=&bRegex_2=false&bSearchable_2=true&bSortable_2=true&mDataProp_3=3&sSearch_3=&bRegex_3=false&bSearchable_3=true&bSortable_3=true&mDataProp_4=4&sSearch_4=&bRegex_4=false&bSearchable_4=true&bSortable_4=true&mDataProp_5=5&sSearch_5=&bRegex_5=false&bSearchable_5=true&bSortable_5=true&mDataProp_6=6&sSearch_6=&bRegex_6=false&bSearchable_6=true&bSortable_6=true&mDataProp_7=7&sSearch_7=&bRegex_7=false&bSearchable_7=true&bSortable_7=false&sSearch=daria&bRegex=false&iSortCol_0=6&sSortDir_0=desc&iSortingCols=1&
=1543138609685 HTTP/1.1” 200 1840 “https://billing.MyDomain.co.uk/clients” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:36:52 +0000] “GET /clients/608 HTTP/1.1” 200 22315 “https://billing.MyDomain.co.uk/clients” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:36:52 +0000] “GET /css/select2.css HTTP/1.1” 200 0 “https://billing.MyDomain.co.uk/clients/608” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:36:52 +0000] “GET /api/recurring_invoices/608?sEcho=1&iColumns=8&sColumns=%2C%2C%2C%2C%2C%2C%2C&iDisplayStart=0&iDisplayLength=10&mDataProp_0=0&sSearch_0=&bRegex_0=false&bSearchable_0=true&bSortable_0=false&mDataProp_1=1&sSearch_1=&bRegex_1=false&bSearchable_1=true&bSortable_1=true&mDataProp_2=2&sSearch_2=&bRegex_2=false&bSearchable_2=true&bSortable_2=true&mDataProp_3=3&sSearch_3=&bRegex_3=false&bSearchable_3=true&bSortable_3=true&mDataProp_4=4&sSearch_4=&bRegex_4=false&bSearchable_4=true&bSortable_4=true&mDataProp_5=5&sSearch_5=&bRegex_5=false&bSearchable_5=true&bSortable_5=true&mDataProp_6=6&sSearch_6=&bRegex_6=false&bSearchable_6=true&bSortable_6=true&mDataProp_7=7&sSearch_7=&bRegex_7=false&bSearchable_7=true&bSortable_7=false&sSearch=&bRegex=false&iSortCol_0=0&sSortDir_0=desc&iSortingCols=1&=1543138615334 HTTP/1.1" 200 6716 “https://billing.MyDomain.co.uk/clients/608” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:37:14 +0000] “GET /css/cookieconsent.min.css HTTP/1.1” 200 1029 “https://billing.MyDomain.co.uk/recurring_invoices/create/608” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:37:14 +0000] “GET /css/quill.snow.css HTTP/1.1” 200 4096 “https://billing.MyDomain.co.uk/recurring_invoices/create/608” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:37:13 +0000] “GET /recurring_invoices/create/608 HTTP/1.1” 200 223239 “https://billing.MyDomain.co.uk/clients/608” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:37:14 +0000] “GET /images/lightbox/prev.png HTTP/1.1” 200 1360 “https://billing.MyDomain.co.uk/css/lightbox.css” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:37:14 +0000] “GET /images/lightbox/next.png HTTP/1.1” 200 1350 “https://billing.MyDomain.co.uk/css/lightbox.css” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:37:14 +0000] “GET /images/lightbox/loading.gif HTTP/1.1” 200 8476 “https://billing.MyDomain.co.uk/css/lightbox.css” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:37:14 +0000] “GET /images/lightbox/close.png HTTP/1.1” 200 280 “https://billing.MyDomain.co.uk/css/lightbox.css” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:38:06 +0000] “POST /invoices HTTP/1.1” 403 1139 “https://billing.MyDomain.co.uk/recurring_invoices/create/608” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:38:19 +0000] “POST /invoices HTTP/1.1” 403 1139 “https://billing.MyDomain.co.uk/recurring_invoices/create/608” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:38:25 +0000] “GET /recurring_invoices HTTP/1.1” 200 15674 “https://billing.MyDomain.co.uk/recurring_invoices/create/608” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:38:25 +0000] "GET /api/recurring_invoices?sEcho=1&iColumns=9&sColumns=%2C%2C%2C%2C%2C%2C%2C%2C&iDisplayStart=0&iDisplayLength=100&mDataProp_0=0&sSearch_0=&bRegex_0=false&bSearchable_0=true&bSortable_0=false&mDataProp_1=1&sSearch_1=&bRegex_1=false&bSearchable_1=true&bSortable_1=true&mDataProp_2=2&sSearch_2=&bRegex_2=false&bSearchable_2=true&bSortable_2=true&mDataProp_3=3&sSearch_3=&bRegex_3=false&bSearchable_3=true&bSortable_3=true&mDataProp_4=4&sSearch_4=&bRegex_4=false&bSearchable_4=true&bSortable_4=true&mDataProp_5=5&sSearch_5=&bRegex_5=false&bSearchable_5=true&bSortable_5=true&mDataProp_6=6&sSearch_6=&bRegex_6=false&bSearchable_6=true&bSortable_6=true&mDataProp_7=7&sSearch_7=&bRegex_7=false&bSearchable_7=true&bSortable_7=true&mDataProp_8=8&sSearch_8=&bRegex_8=false&bSearchable_8=true&bSortable_8=false&sSearch=&bRegex=false&iSortCol_0=4&sSortDir_0=asc&iSortingCols=1&
=1543138707967 HTTP/1.1” 200 109147 “https://billing.MyDomain.co.uk/recurring_invoices” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:38:28 +0000] “GET /recurring_invoices/create HTTP/1.1” 200 223118 “https://billing.MyDomain.co.uk/recurring_invoices” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:38:28 +0000] “GET /css/lightbox.css HTTP/1.1” 200 887 “https://billing.MyDomain.co.uk/recurring_invoices/create” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:38:28 +0000] “GET /css/quill.snow.css HTTP/1.1” 200 12288 “https://billing.MyDomain.co.uk/recurring_invoices/create” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”
83.42.134.164 - - [25/Nov/2018:09:39:12 +0000] “POST /invoices HTTP/1.1” 403 1139 “https://billing.MyDomain.co.uk/recurring_invoices/create” “Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0”

That looks like the access log, not the error log.

Which file am I looking for please…?

On my computer it’s: /var/log/apache2/error.log

You may want to ask your webhost for help.

Where might I find this on a shared resller account…?

I found this, don’t know if it helps…

It coincides with the save eerors though…

2018-11-27 13:25:10.740359 [INFO] [83.42.134.164:55536:HTTP2-15] File not found [/home/billingwhatnoweb/public_html/403.shtml]
2018-11-27 13:23:03.957745 [INFO] [83.42.134.164:54977:HTTP2-85] File not found [/home/billingwhatnoweb/public_html/403.shtml]
2018-11-27 13:22:59.371266 [INFO] [83.42.134.164:54977:HTTP2-37] File not found [/home/billingwhatnoweb/public_html/403.shtml]
2018-11-27 13:22:30.658543 [INFO] [83.42.134.164:54977:HTTP2-35] File not found [/home/billingwhatnoweb/public_html/403.shtml]
2018-11-27 13:18:22.602471 [INFO] [83.42.134.164:53931:HTTP2-33] File not found [/home/billingwhatnoweb/public_html/403.shtml]
2018-11-27 13:17:40.748246 [INFO] [83.42.134.164:53931:HTTP2-31] File not found [/home/billingwhatnoweb/public_html/403.shtml]
2018-11-27 13:15:33.829422 [INFO] [83.42.134.164:53522:HTTP2-69] File not found [/home/billingwhatnoweb/public_html/403.shtml]
2018-11-27 13:15:27.274738 [INFO] [83.42.134.164:53522:HTTP2-67] File not found [/home/billingwhatnoweb/public_html/403.shtml]
2018-11-27 13:15:17.421909 [INFO] [83.42.134.164:53522:HTTP2-65] File not found [/home/billingwhatnoweb/public_html/403.shtml]

Sounds like a security rule.

Try disabling ModSecurity for that sub domain and see if you can save the invoice.

That appears to have worked.

Now, how do I work around this or would it just be simpler to leave ModSecurity disabled…?

Ask your web host to remove the rule that is being triggered.

I would not recommend leaving ModSecurity off.

There appears to be another problem too, the system says it is sending mails but when I test nothing is received at all.

Is proc_open enabled?

Have a look on the invoice overview screen, if there is an issue, it shows an information triangle (think it’s next to recipients email address top left)