The "Database is locked" error occurs when you try to access a file that is currently in use by another process. For example:
You have a Word file that you want to delete, but the system displays the following message:
This error usually occurs in a program when an action was terminated incorrectly or abruptly, leaving the session file occupied by an unfinished process, and the system won’t let you access it.
How to fix it?
The solution is very simple: completely close the program (not just the browser window), and if the cause was an improper termination of the process, the error will disappear. If the error is caused by a third-party program, you’ll need to close it. To find out which program is holding the file, try deleting it; Windows will notify you which program is preventing you from performing the action.