Hello! Don´t know if this is the right forum (hopefully), but anyways: I created a PDF form in LibreOffice Draw and made fillable text boxes. Result: working fine in Linux, but trying to fill any data (numbers) into the text boxes using a windows computer gives you only dots instead of numbers. Anybody know the reason? Is it the wrong standard (PDF/A) or what, should it be converted into PDF, or what?
Thank you in advance, any help would be most appreciated!

Check your encoding formats between the libreoffice making the file and that of your windows working environment. If you have created it in a UTF-8 character encode you should try using it under windows being set at UTF-8. This may heal the problem.
However, there is a general narrow-minded tendency of proprietary OS's (notoriously MSWindows) to create a built-in denial of such cross-platform usability. If this is happening in your case, better try another pdf creator software --there are plenty in the FOSS sources.

Good luck. Hope that helps.

2 members found this post helpful.

Know what?

I solved it, by doing some trial and error things I found out that the Windows OS was not able to create the font Liberation Sans, so I switched to Arial, and Heureka! Thanks for mentioning UTF-8, that got me thinking!

Glad to hear that. Windows don't (probably) have Liberation Sans, it has Comic Sans though.
Congrats and enjoy.