I'm quite sure, that deinstall and reinstall will fix it - but it's not about me. I see myself as "Beta Tester" (I guess, that's the aim of Beta Software) so I fear many others will get the error.
I installed the 32 bit in "C:\Program Files (x86)" and did only "Update" installations, so at any point it must has been moved to C:\Program Files (but not by me ;-))
Of course I will deinstall and re-install (latest with the next build) - but as said before I am quite sure it will fix this and this would mean, that we have to tell any other user, experiencing this error, to deinstal and reinstall...
OK, while starting the uninstall, I see, what happens:
3.16a still is installed in C:\Program Files (x86) - as there was any MP3Tag built before.
Now 3.16b tries BY DEFAULT not to install in the existing "x86"-Folder but in C:\Program Files - this causes the error.
So if 3.16b is set to install in C:\Program Files by default You maybe might built in a deinstall routine for C:\Program Files (x86) before...
(I will do it manually now)