Correcting cert error in Firefox on Ubuntu

I have been making changes to my network including rebuilding PF Sense and changing my network IP address scheme. I got the network up and running fine and began re configuring Truenas including the IP addresses and vlan’s it can be connected to.
The problem I am having is I can’t connect to True NAS via Firefox anymore because of a Cert error:

“An error occurred during a connection to You are attempting to import a cert with the same issuer/serial as an existing cert, but that is not the same cert.”

I have tried to delete most of the certs under security on the servers tab in Firefox tools but to no avail. Are certs stored in the Linux system that could be causing the problem or is there another way to get this working.
I can connect using Edge from my windows box but that is not the way I want to continue to administer my systems.

I found a solution. I removed Cert8.db and renamed cert9.db and cert_override.text adding old to them both and now It asks for an exception instead of rejecting the connection completely. The difficult part was finding the location of the files.