This issue is due to presence of Cisco bug ID CSCsa51115.
In this issue, this error message is logged with traceback:
%AAAA-3-INVSTATE: unknown AUTHOR/EXEC: Internal state is invalid: astruct 0x487EF918 ustruct 0x0-Traceback= 403FBE40 403FBD80 40445758 40445108 40461CDC 40471848 4118C9E0 4118076840FBE6C0 40FBE6AC
This is a rare and unreproducible issue and is considered as cosmetic. No troubleshooting or image upgrade is required for this issue.