500 Internal Server Error due to project names

I have experienced a bug when trying to export my projects named like "WSI ćw. 7 zad. 1" to an image file.
I was getting the "500 Internal Server Error" consistently on multiple platforms, PCs, browsers and even shared users. I could export it to XML and re-import it correctly, but the image export remained bugged in the new file as well.
I have found out, that it was due to the name of the project. When changed to "WSIlab7ex1" it worked perfectly fine. I haven't found out precisely whether it was due to the special character "ć", the "." (dot) or the " " (space), but one these three is a culprit.
Hope, you'll at least some info to the error, as there's no feedback and it was blind luck permitting me to find out, what was the issue.

Love the platform BTW, great job guys!