I don't know if I should be reporting this here, but it's translation related.
In the build menu information about the translation file is appearing and I believe it shouldn't.
The attached screen-shoot explains it better than words.

I tested with pt_PT, pt_BR, de_DE, en_GB and en_US, by executing geany from the console with  LANG=pt_PT.utf-8 geany
Only in the latter (en_US) there isn't any problem.

Kind Regards,

Ps: Thanks for the "Add custom filetypes features" I have some friends that will be changing to Geany because of that.