Search the Knowledge Base for 'red plus' and you will find several articles outlining several possible causes.
I get this when the IT department deletes a user in active directory or the AD is not found by PDM.
But anyway 2014SP5 is also released now.
We experience this here as well.
When we created our EPDM Vault, we have lo-gins tied to Windows log ins. There is option when you create the Archive Server under SECURITY to select which AD groups have access. (our is called SolidWorks_Users)
To define the Windows user accounts that are allowed access to this archive server, by select the accounts under Available users and groups and click the arrow pointing to Administrative access or Attach access.
We noticed that if users have not been specifically added to this AD group, they get a red plus sign in EPDM. Even though they have a user (created in EPDM admin tool) can still log in. Adding them to the AD group fixes this.
I did upgrade successfully the production vault and I didn't experience this issue again (No Red Plus). The only thing that I did different which I didn't do in the test vault is I didn't block users log-ins before the upgrade, Of course I made sure that no one is logged in.