If you are seeing erroneous license expiration messages on the server, it is likely that the host machine is reporting an incorrect time. The license manager in your RStudio Workbench (previously RStudio Server Pro) periodically contacts our license server to verify that the license is still valid, and this license server is extremely particular about date-time precision between the server and client. If your host machine's clock is off by even a few seconds, the license server may reject the request and report the license as expired.
Fortunately, this can generally be remedied with these steps:
1. Make sure the time zone is correct for the machine.
2. Resync the date and time of the machine.
3. Restart the machine (not just RStudio Workbench; the whole machine).
Finally, run this command on the server to verify success:
sudo rstudio-server license-manager status