Recently I had the following difficulty - when I tried to open .mpp through my file manager list or from recently opened files, .mpp doesn't open due to an inexplicable reason for me. When I try to just open the program and then manually go to the folder where .mpp is located, and open the file in this way, Project actually ceases to respond to any commands and hangs with the computer. What could it be?

The best solution in case nothing helps could be microsoft project recovery
Visit microsoft article on - https://support.microsoft.com/en-us/help/323330/how-to-back-up-schedule-and-restore-a-microsoft-project-server-databas
This is the resource of manual: http://project.mvps.org/faqs.htm#Handling_project_file_corruption_and/or_bloat
Or alternative variant can be https://project.recoverytoolbox.com/