Well, that error message isn’t particularly helpful.
Which version of FreePBX and Asterisk are you running? I would probably start by making sure that FreePBX and all modules are up to date: fwconsole ma upgradeall
Actually, it is. We’ve seen it before, usually when the Caller ID field has an error in it. Check your extension, outbound route, and trunk configurations and make sure the Caller ID is set and set correctly.
I mean, it’s a generic dialplan error, it could be anything. I am confused what you mean by Caller ID field has an error in it. Are we allowing bad data to be pushed to dialplan?
There are plenty of examples (at least 20) where this error message comes up. Some are solved by core changes, some by making sure all of the variables associated are filled in correctly. The proximal cause is that a variable is blank and isn’t interpreted by Asterisk correctly, causing the comparison to fail. The tricky bit is figuring out what isn’t filled in.
This is a similar discussion from 2019. Something in the setup is blank, causing the comparison to fail. A similar example from 2016.