HTTP 500 Error When Customers Try to Edit Listings

I also have a support ticket in on this issue, but since it’s been taking a while to get an answer, hoping I can get some help here.

Classified Theme Version 8.9.6 (working beautifully for years)
On the Admin side, everything is working 100%

On the User/Customer Side, they are receiving HTTP 500 Internal Server Error when they try to View/Edit their own listing through their Dashboard.
50% of the time, they receive the same error when trying to view any listing on the site, not just their own.
There doesn’t appear to be any issue with Adding New Listings.

Not sure how long this has been an issue, as the site functions normally on the admin side, and new listings were being submitted successfully by customers. Just the other day a customer reached out to me to let me know they were experiencing issues with the site. I created a customer account and saw the same errors they were experiencing.
A recent error log attached that you guys can probably understand better than me.
site; http://www.floridasporthorse.com

Help! (and thank you!)