Annette Allen had a service pack installation go south due to missing MSIs:
I was recently doing a service pack, I’d run it on the entire test estate and half of the Production estate, I’d used Pinal Dave’s really useful AG check list and been really overcautious, I’d finished integrity checks on all databases, I’d backed everything up and even had a snapshot of the server completed.
When I clicked on the service pack I got the error “missing MSI” sorry I don’t have the screen dump or the full error message because at the time of trying to fix it I did’t think to take a copy
Read on to see what the root cause was and how Annette was able to fix this error.