I found the reason. It turned out that despite uninstalling OneDrive, there were registry entries pointing to the \Users\Name\OneDrive\Documents (and desktop) folder, not Users\name\Documents. After changing the registry, everything is fine.

The same problem:
How do I block the menu from opening when returning to Opera via Alt-tab?
It's terribly irritating and unergonomic.

I found the reason. It turned out that despite uninstalling OneDrive, there were registry entries pointing to the \Users\Name\OneDrive\Documents (and desktop) folder, not Users\name\Documents. After changing the registry, everything is fine.

I have uninstalled OneDrive from my computer and removed all folders with OneDrive. From this time when I try to save e.g. picture I receive every time message: Location C:\users\Danny\OneDrive\Desktop is unavailable. If this location is on your computer...
How to get rid of this message?

@leocg
It is my search engine in section Others. If I add another one now, I can edit or remove it, but what I added earlier is like in the screenshot - Edit option is gray and no Remove.

Neither I can edit own browser nor remove - the option is grey, I can only set it as default.. What is solution?