Problem with game launch

[Phoenix]

Hello, I have come upon a problem whith this game. I have played it for about 40 hours without any problem but then I have put the game in windowed mode and moved the window to my second screen. After that I changed the resolution to fit my screen and game just crashed. When I opened the game again it showed just the close and minimize icons in wondowed mode and nothing else. When I used alt+enter to get to full screen it is just a field of light blue color that the app uses for background. It doesn't even show you the menu. I did the same thing with the THERMO sudoku app from the same developer and the identical thing happened. I haven't tried it with the other apps so I don't know if the same thing would happen with them too. I unnistalled both the games and installed them again but that didnt help. I have no idea what have I done that caused both games to fail in such a way. I have never before had any problems with any of the apps from Cracking the Cryptic and are really grreat and I really enjoy the puzzles. But now I have no idea what I have done to cause them two of them to fail in such a way. If anybody has any idea how to fix it I would be most grateful.

[NickCarney94]

For some reason the resolution can get set to 0x0 sometimes. You can fix it by following these steps:

1) Press Win + R or search for the Run application.
2) Type in regedit and click open.
3) In the registry editor, navigate to HKEY_CURRENT_USER > Software >Studio Goya.
4) Right click on the Killer Sudoku folder and select delete, this should reset everything to the starting values. (Your save file should not be affected by this.)

[Phoenix]

Thank you! Sorry for the late reply, but it waasnt a period with much time for games. Your solution worked great. Thank you again and looking forward for more apps :)

[NarcoWiz]

Yay! Thank you. Worked for me too!