c8fa26c0_Internal_Error_Codes___DocWiki__Descriptor
[Code] 13 [Explanation] An internal software error occurred. Report the entire IEC string, including the diagnostic code field, to customer support. [Category] 180 [Descriptor] 
Software error
Cisco IOS Voice Troubleshooting and Monitoring -- Cisco VoIP Internal Error Codes - DocWiki
Descriptor