When you say cleared client cache, cache folder and cache in AppData do you mean on the server? This definitely feels server side since restarting the server fixed the issue. We did have a couple of users clear their cache but were still getting the error about every other time they opened the app.
Guys, I think I might have hit on a thread here with the same issue. It’s with Kinetic and slightly newer version but wondering if it could be a licensing setting or Named Pipes not being enabled on the SQL server. I did see errors related to Named pipes in the event log and the error that was happening that week was tied to licensing.
Installation of Kinectic 2021 - Kinetic 202X - Epicor User Help Forum (epiusers.help)