Is there a chance that the crpg installer/Launcher intervenes with mouse drivers?
The following i have noticed:
I had the problem that the mouse bindings weren't recognized anymore, only the default 2 mouse buttons are still of use.
After reinstalling mouse software and speaking 2-3 hours with Logitech customer support on the phone, i was able to confirm that the mouse works proper in other programs but still not in crpg.
So i made a complete new clean Mount&Blade installation and there then it worked again.
Then i installed crpg with the latest installer and it wouldn't work, when i started it with the installer.
BUT when i started crpg without the installer, i was able again to define mouse bindings within Options/Control, which wouldn't work while starting crpg with the installer.
So i normally come to the conclusion that something between starting crpg with the installer and without it must have happened to cause my mouse problems.