File access is a file system, not a hard drive. At the very beginning, I wrote that I ruled out this problem.
Reread the first message.
The browser is launched "from under the administrator", the folder is given "write" permissions for all accounts.
Until a certain moment everything was rocking fine, now with Vimeo it began to write like that. I think something was updated in Vimeo itself, but they did not begin to refine it in the plugin code.