Symptom
Unable to save or save and apply external authentication objects with AD. The following error is seen in the GUI: Can't use string ("") as a HASH ref while "strict refs" in use
Even the creation of new external authentication objects or FMC does not resolve the problem.
Conditions
FMC external authentication
AD configuration for external authentication object
Workaround
1. Log into the FMC CLI.
2. Go to expert mode:
expert
3. Execute the following command to clear a directory of data files used by the credentials vault on the FMC (when prompted, enter the password for the logged-in CLI user):
sudo rm -rv /var/lib/vault/sys/counters/requests/
4. Restart the VaultApp process (if prompted, enter the password for the logged-in CLI user):
sudo pmtool restartbyid VaultApp
5. On the FMC GUI, navigate to (System > Users > External Authentication).
6. Click "Save and Apply" to attempt to apply external authentication configuration to the FMC.
