D100 5.6.1 update can't find A/P servo

[TriQ Jockey]

Last Updated D100 2015. Worked fine up until I did 5.6.1. Update "successful". A/P74 panel lights stay on during update and will not operate A/P after update. EIS appears to be fine. No maintenance done to system between last flight and attempted update. Have reconfigured and attempted several updates. No success.