When creating a New Project, Unity fails to start and a message comes back requesting Please move the project folder somewhere readable and writable
check windows defender virus and threat setting and uncheck controlled folder access.
More than likely, your project folder is in a READONLY section of your harddrive. You need to put it somewhere public, usually it is in Public Documents.
Make sure that you have enough space on your harddrive.
My harddrive had 0 Bytes free space, after deleting some files it worked again.