Resolution: Ferrilli discovered the issue was related to permissions on the LDM.GUID file. This issue was related to file maintenance that was done the previous evening by Ferrilli - Sept. 4th at 10pm ET. The issue was affecting Colleague mnemonics other than XENS.
Going forward, whenever file maintenance is performed for LDM.GUID, Ferrilli will need to check permissions on that file and make sure there is write and execute access for the LDM.GUID file.
Ferrilli consultant made the permission changes to the LDM.GUID file in Production and that resolved the issue.