FlexNet licensing error -4: Licensed number of users already reached
All suitable licenses are already in use.
A license file provides a fixed number of seats for each component. If all the seats are in use, further requests will not be satisfied. Normally, the server will queue a request until a seat becomes available so that the client does not see a failure.
On the client you might see something like this:
Waiting for license...
License check-out is queued in the license back-end
There are cases where this queuing mechanism fails, and when the client gives up on queuing the license you would see this error message on the client.