Field Render Failed (Error after Upgrade to Release 25.1.0)

I've opened a Case, but it's the weekend and I'm thinking I may not get help until all of the users start complaining on Monday morning.

The upgrade to 25.1.0 happened last night and when I open an Account or Contact record the error reads:

"Field Render Failed: Unable to render the panel_dropdown field.Please contact technical support."

I'm trying to find out why and get it corrected.

Does anyone have suggestions?