Can you check your log again? Right before this error there should be another log entry which contains the actual exception.
Passwords tries to find a matching words service automatically. The passwords service requires a locally installed dictionary and/or access to a cryptographically secure source of randomness on your system.
You can check the currently used password generator in the admin settings.
I didn’t see the logs entries you mentioned, but I changed my password generator to watchout4snakes.com and now the password generation is working correctly. I wonder what the local dictionary should be on FreeBSD, but at least it is working well now. Thanks for the hints!