https://bugs.winehq.org/show_bug.cgi?id=45417
--- Comment #8 from Silvan s.jegen@gmail.com --- (In reply to Zebediah Figura from comment #7)
(In reply to Silvan from comment #6)
(In reply to Zebediah Figura from comment #5)
Hmm, it seems like it doesn't work on 64-bit for some reason. If your program is 32-bit you could try in a 32-bit prefix.
Currently our program is only 64-bit but I have to compile a 32-bit version anyways. I will do that next week and check that one with windowscodecs in a 32-bit prefix.
FWIW, it should also work if you manually edit the winetricks script to set the version to win2k3 instead of winxp (function "load_windowscodecs"). See https://github.com/Winetricks/winetricks/issues/970.
I edited the file manually and then installing the codecs worked. When running our app there was no difference between before installing them and after however.
I agree that this will be a difficult thing to debug. If you think it would help, I can upload the big trace somewhere for you to download?