About diagram locking

When a user accesses a diagram it becomes locked in order to prevent other users from changing it. A lock can also be caused by another user performing, or waiting to perform, a restructuring operation, for example resetting ID numbers, inserting a diagram, etc. The diagrams affected by a restructuring operation will remain inaccessible until the operation is complete.

After a period of user inactivity (set in the system options) the lock will be automatically released and the diagrams can then be accessed.