The license server crashes, hangs, or stops serving licenses and complains about file descriptors.
The server debug log file reports the following (or a variation):
7:02:11 (mgcld) This license server system can handle no more
7:02:11 (mgcld) concurrent clients since it is out of file descriptors.The license server has run out of system resources.
Use the ulimit command to display and increase the number of available file descriptors in the license server environment.