This article was created in response to a support issue logged with K2. The content may include typographical errors and may be revised at any time without notice This article is not considered official documentation for K2 software and is provided “as is” with no warranties.

Issue

K2 service cannot start and goes into a starting state. 
When rebooting the K2 server or ending the process task the behaviour remains the same.

Looking at the service in console mode you notice the error:
"Received socket exception with error code 10054 connection reset"

Symptoms

In console mode it will start, however the SQL process will skyrocket and the server performance will drop dramatically.

Troubleshooting Steps

Open resource manager in SQLMangement Studio.

Notice the following script executing from the K2 server running in console mode:

SELECT lu.[TempFQN], COALESCE(id.[DisplayName], sl.[SecurityLabelName] + N':' + scc.[UserName]) AS [UserName], sl.[SecurityLabelName] FROM [LicensedUsers] AS lu LEFT JOIN [SecurityCredentialCache] AS scc ON lu.[CredentialID] = scc.[CredentialID] LEFT JOIN [SecurityLabels] AS sl ON scc.[SecurityLabelID] = sl.[SecurityLabelID] LEFT JOIN [Identity].[Identity] AS id ON id.[FQN] = sl.[SecurityLabelName] + N':' + scc.[UserName] WHERE lu.[UserType] = @UserType

Notice that the LicensedUser table was close to 8000 entries.

This table was required for 4.6.11 and no longer necessary in K2 4.7 and up.

Make an SQL backup and truncate the table. This does not affect the server or users in any negative way.