Could not lock the database (Error 536)

The database file could not be locked. This error has the following causes and solutions:

• You tried to lock a table while opening it, but the table can't be locked because it is currently in use.

  Wait a moment, and then try the operation again.

• You tried to lock a record that is currently locked by another user.

  Wait for the other user to finish working with the record, and then try the operation again.