There are many different things that could be wrong and without an error message we can’t really give you a specific solution but here are several things I’d try.
Verify permissions – does your account still have same permissions
Verify database is not corrupted – try using DBCC CHECKDB
] for this
Try restoring database from backup if possible and see if everything is ok there.
I doubt this is the case in your problem but i had many complains lately with similar issues and after extensive investigation we realized SSD hard drives can be the cause. Just wanted to share this for the future readers