A customer ran into this issue where they can't move the cursor in the text editor and other things didn't work such as control-Z and import/export settings.
The workaround is:
- Shutdown Visual Studio
- Click Start -> Run
- Type in "devenv.exe /resetuserdata"
- Open Task Manager and wait for devenv.exe to finish running
- Restart VS
Thanks goes to James Lau for providing the workaround for this.