Error Code -4 Licensed number of users already reached on Launch of Opcenter APS.
When trying to launch Opcenter APS, the network license is not found (the Activate Opcenter APS dialog appears, and keeps appearing).
When right clicking on the title bar of the Activate Opcenter APS dialog, and choosing Advanced Details, the following dialog reports:
Checkout of '[LicenseNumber]' failed with code -4 - Licensed number of users already reached.
When checking the Preactor.log (under C:\Program Files (x86)\Siemens\Network License Manager\logs), the following line is detailed:
7:46:53 (PREACTOR) DENIED: "user_defined_configuration" [UserName]@[ComputerName] (Licensed number of users already reached. (-4,342))
Firstly, check that the number of licensed users has not already been reached.
If the Count equals the number of seats for that license, then a user will need to close out of Opcenter APS, to allow the other user to use the license.
If the Count has not been reached, there may be another reason for the message. Sometimes stopping and restarting the Vendor Daemon can solve the issue (note that you will want to inform users currently using Opcenter APS that you are restarting the Vendor Daemon, and they should save any work and come out of Opcenter APS).
If stopping and restarting the Vendor Daemon is not successful, the licensing services can be stopped and restarted through the Windows Services App.
This error message is also known to occur due to an issue that existed in Opcenter APS 18.1 and lower versions where checks were made by the licensing system on the validity of features already checked out, and due to an incorrect response, the result was that the licensing system tried to log out some different features instead that didn't belong to that license. This issue is resolved by installing Opcenter APS 18.2 or higher, and Network License Manager 18.2 or higher.
NOTE: An issue that was introduced with the Network License Manager dashboard in Opcenter APS 18.2 is resolved in Network License Manager (NLM) version 2204 and higher.