Locked documents originated in Writer: What locks them? How do I unlock them?

There seem to be problems with saving documents as well: are those problems related to the lock problem?

What problems do you mean? Perhaps you could edit your question to add helpful information such as error messages and operating system.

If you are on Windows have a look at question 308405

If you are on MacOS have a look at question 308365

If neither the please supply info requested by robleyld above