This is a SQLITE_READONLY error (code 8).
The SQLITE_READONLY result code is returned when an attempt is made to alter some data for which the current database connection does not have write permission.
Database errors occur more frequently with networked or shared project files. It is best to work locally on a single machine and then after the project is saved and closed, transfer it to the networked drive.
If moving the database to the local drive does not correct the problem, try to repair your project, see: Corrupt or Otherwise Broken Audacity Project Recovery