I do not know what i did wrong, but suddenly all my movie ( every cut) went unsharp,not only the one I was editing. How to reverse this? " undo" in the edit section dit not go so far back. Work with magic movie edit PRO
Hard to say without more information, but I'd start by trying three basic 'resets':
1. F9 to restore standard layout.
2. Right click in preview monitor > Resolution presets > Restore your normal choice if it's somehow been changed.
2. File > Settings > Reset program settings to default to restore all basic settings.
If none of those work you'll have to give us much more information including at least which version of MEP you are using and a clear, readable screenshot of your timeline, illustrating the problem.