This is a mode specific to the Network version, allowing the SPR and authorized users to work alone on a base, the other connected users are alerted by an information message are automatically transferred to Consultation mode and can no longer act on the base. They will transfer back to Modification mode once the Exclusive Usage mode has been closed.
This mode is automatically activated at the launching of some commands (automatic placement, optimization, etc.). Otherwise, it is always the user that chooses to quit this mode.
In Exclusive Usage mode, the data is not saved as you go. If you do not save it manually [Ctrl + S], EDT requests a confirmation for a safeguard when you quit this mode.
Go to the menu File > Utilities > Enter in "Exclusive Usage" mode.
Go to the menu File > Utilities > Quit the "Exclusive Usage" mode or click on the button in the tool bar.