We updated from Sage 300 version 2020 to 2022. Webscreens is not working and gives the following error upon Login: "Unexpected Error: An Unexpected problem has occurred. Please try again or contact your administrator for assistance."

I've been researching this and believe the cause is that the Sage 300 .NET Remoting Service won't start. When I try to start this service, I get this error: "Windows could not start the Sage 300 .NET Remoting Service service on Local Computer. Error 1064: An exception occurred in the service when handling the control request."

Chasing that error down, the Event Viewer has this in the Application Log: a4wnetMgrService - "Service cannot be started. System.ApplicationException: Could not locate registry entries required by the ACCPAC .NET Remoting Manager Service. at ACCPAC.Advantage.Server.RemotingManagerService.OnStart(String[] args) at System.ServiceBase.ServiceQueuedMainCallback(Object state)

I'm not sure what registry entries are required (presumably in HKLM\SOFTWARE\WOW6432Node\ACCPAC International, Inc.\ACCPAC\Configuration\ ?) or why the installer didn't take care of it.

Has anyone seen this problem or have any suggestions how to go about fixing it?

EDIT: 

The problem ended up being Orchid's Extender, with the latest PU reading "Sage 2022 PU2 removed a function that Extender was calling which caused
Extender to not run in the web screens. This PU fixes that."

One additional thing - The login with the Admin account is disabled by default for Web Screens. It can be enabled by changing the key for "AllowWebApiAccessForAdmin" from false to true in the web.config files.

Adding this as an Edit and not a comment that I could mark as a solution because I keep getting a "An error occurred. Please try again or contact your administrator." when trying to post a comment.