Hello.
I had rebound camera rotation on RMB (it's MMB by default, as I could remember)
Now it's weird behaviour: first, you start moving to some point (LMB), then rotate camera (with RMB), and you got cancel of moving. :-\

Could you fix it, please?

Remap, or remove, the secondary hotkey for 'Cancel Action' in the Controls section of the options (at the top of the third group of hotkeys). The right mouse button is also the default hotkey for 'Context Menu', immediately below that.

Thanks!

Hmmm. Its resets after game restarting

Remap the secondary hotkey to something you wouldn't otherwise use, then (Shift / Ctrl / Alt + something), rather than just clearing it. The game 'fixes' some function hotkeys that are 'missing' on startup.

and it still resets each time when the game starts.
anyway, you could handle keyup/down/press in combat ('press' to cancel of spell casting) or 'down' when rotating camera.
plzplzplz ^_^