Notes On Deleting License Keys 

●      Never delete “obsolete” license keys if you do not have an active license key. The system needs this information to decide whether a temporary license can be installed (more information: Installing Temporary License Keys, Prerequisites section).

●      You should not delete the currently active license key (this is the one highlighted in transaction SLICENSE). If you want to do so, you should first install a (temporary) license key so that other users can log onto the system.

●      The status of a license is not checked when a license key is deleted. In particular, there is no check to establish whether you are deleting a license key that is currently in use. If you delete a valid license key that is currently in use, no users will be able to log onto the system from this point on (exception: user sap*). Users who are currently logged on, however, can continue to work.

If, by mistake, you delete a valid license key currently in use, you can reinstall it at any time. See transaction SLICENSE. The prerequisite is that you have kept your license key.

●      The existence of old license keys that are no longer used do not affect the operation of your SAP system. Nevertheless, it is advisable to delete license keys that are no longer used (Performance optimization during the license check).

You can recognize temporary license keys that are based on old license keys by the characteristic, CUSTOMER KEY = TEMPLICENSE. You can recognize temporary license keys that are based on new license keys in the table Licenses in the Database in column Type (Perm or Temp).  Deleting temporary licenses does not mean that you can install further temporary licenses (see also Installing Temporary SAP License Keys).