I have had this happen several times in the PCB editor.
If I go to the Route->layers Settings dialog, sometimes it won't close and I end up having to use task manager to kill the PCB process.
No particular order of doing things, sometimes I just open the dialog, look at something and it wont close.
I see this on 4.1.2 and the previous version
Joel
Layers Settings dialog hangs
Re: Layers Settings dialog hangs
Please run regedit, select HKEY_CURRENT_USER\SOFTWARE\Novarm\DipTrace\ tree and export it to a file. Send reg file to DipTrace support for verification. Find default.reg file in DipTrace folder and run it. That will reset DipTrace settings in Windows registry to default.