I use the dutch version of IN5.
On the client page i cannot select the Polish (Pools) language.
To add the Polish language i have to set my settings to English and the select Polish.
When i go back to Dutch it is OK.
I ckecked the dutch translation on Transifex ans saw that there was a return sign after the translation.
I removed it.
So i hope it’s fixed on the next update of the languages.