Hey @mkriznjak ,
I think I found the solution. On my PC it worked well
So, firstly you have to go here:
C:\Users\ userName \ .nuget\packages\uipath.vision\3.1.4\build\net461\tessdata
and you have to copy polish language:
pol.zip (8.6 MB)
Next you have to restart you UiPath Studio and everything should works fine
I hope it helps you