Symptoms

Unable to connect to wrongk2servername] on port 5252. An attempt was made to access a socket in a way forbidden by its access permissions.

The process instances that this message is seen for in Error Profiles is relating to a process that is either an IPC parent or child.
 

Diagnoses

The source of this error was determined to be a result of restoring another environment's databases to a new environment for testing, and the child IPC processes that had been started on the other machine were getting lost when trying to return back to the parent.
 

Resolution

There are a set of script in which to remedy this error by changing the server connection strings for items in the Server.IPC table and Server.IPCReturn tables in the K2 database.

In order to get ahold of these scripts, please contact K2 Support.

After the scripts are run to repoint the instances in these tables to the new server, then retrying the relevant errored process instances from Error Profiles seems to resolve the issue.