Are you running your database out of a shared folder, perhaps with Google Drive, Dropbox, OneDrive, or one of those services? Because if that's the case, the lock file might be in the process of being backed up by Google Drive, and that's why Access can't delete it when it closes. I know this because I run some of my simple databases out of my Google Drive folder and this happens to me occasionally.

Richard - I moved my file out of OneDrive to my hard drive. I then opened and closed it. The lock file persisted. I'm eager to get this fixed!

Yes, this has happened.  Instead of rebooting, open task manager, scroll down the 2nd list of processes and look for "ms Access" session, right click and kill the process.

This is a pain

John, ending the process in the Task Manager doesn't work for me. And, this issue happens each and every time I open and close my database. So it's crippling me.

I just right click on the Application Icon to close an unresponsive program.

End Task

Less of a pain (and quicker than opening the Task Manager).

John - I now see what you mean by the second list of processes. Yes, that DOES work. Thanks for the tip!

Thanks to all who have helped me with this. However, nothing has helped me prevent this from happening each time I open my Access database. Could it be corrupted? Perhaps I should create a new, blank database and import all my objects into it. Just wondering.

Yeah, killing the non-responsive process is not going to delete the lock file. It'll shut down Access, but it won't delete the LACCDB file. I remember reading something about this recently...

According to GPT:

It seems there's a known issue with Microsoft Access where the lock file (.laccdb) is not being deleted properly when the database is closed. This problem is often due to bugs introduced in certain Access updates. Specifically, one bug was reported in build 14827.20158, where Access remains running in the background even after closing the window, causing the lock file to stay active. This can prevent other users from accessing the database or lead to errors like "Cannot open any more databases" or "Already in use" messages.

In some cases, manually closing the Access process in the Task Manager or rebooting the system can resolve the issue, but a permanent solution often requires rolling back to a previous version of Access that does not have this bug. Additionally, ensuring that all VBA objects are properly closed and performing regular compact and repair operations can help alleviate this issue.

Microsoft has since fixed this in later updates, so make sure you are on the most recent build. If the issue persists, reverting to an older version or manually deleting the lock file when it's safe to do so might help in the meantime.

Looks like this issue was from a couple years ago though. Have you done an Office Update lately?

Richard, My O365 gets updated automatically, and I'm current with the latest. However, I may "roll back" if this is causing the problem. Thank you for the advice.

For your information, I rolled back to the prior release and stopped automatic O365 version updates. This seems to have resolved the problem for now.

OK good. Yeah, I had to roll back a little while ago myself. The Access Team needs to figure this $#@! out.

I had this issue along with multiple access processes starting on their own. I just got very quick with task manager. However, about two or three weeks ago this all stopped and access works just full me now. I am thinking perhaps while Richard was out exploring new worlds this summer he may have brought something worse than a tribble back and it jumped into his code. Maybe Scotty installed nanobots on his server to clean them out.

WE have had a similar problem, in that Access would not remove itself from active tasks, seems to be a bug in the Office 365 version build 2408.
Roll back your office version and see if it solves the issue.

Error 3048 and Hanging Access Task in Version 2408
https://www.accessforever.org/post/error-3048-and-hanging-access-task-in-version-2408

Peter mentioned it already.  I whinned about it last week.  For me it was a recent update to Office. I rolled back to an earlier release... and problem be gone.

I had this problem, too, this morning, and Alex steered me to this link. After rolling back to Version 2407 Build 17830.20166, it looks like my database is working again.

If you have one drive saving it to you c: drive attaches is to one drive.
Map a drive, save the file to that drive