PDF generation / XMLHttpRequest error

I have two companies on my self hosted v5.5.74-C108 server each has their own domain.
Using company # 1, if I select an invoice, then click Send Email, View PDF, the PDF appears on-screen and is successful emailed to the client
Using company # 2, when I click send Email, I receive a lovely “XMLHttpRequest error”, ./storage/logs/laravel.log is empty.

Any idea where I went wrong?

Softaculous did the honors of installing IN on a cPanel box.

More information: the email and PDF are sent when I click “Send”, I do see the PDF preview when I do Settings | Invoice Design | Customize, but not when I do Settings | Invoice Design | Show Preview


Are there any more details about the error in the browser console?

It’s working now - I am not sure why. I did change PDF_GENERATOR to snappdf, however I did that shortly after sending the original request, when I tested the “solution” still no PDF joy, so we have a mystery.