Cheers Nick,
I know these are blinking complex things!
What is frustrating is that all of these were working fine, then when I looked last week were just not there.
I just found the MSFS forum advice below, in respect of a PA-44 addon aircraft that had similarly disappeared, and I tried the solution for KSBA, KORS, KBCE and 3W5 but sadly it did not resolve the issue.
I will keep trying and update this thread if I find success,
Nick
There are several threads about this, but the fix is simple:
go into the Official packages folder (it’s next to the Community folder. If you don’t know where the Community folder is, search the internet for “Microsoft Flight Simulator Community folder” and it will explain how to find this folder depending on where you bought the game from)
go to OneStore under that
delete the existing carenado-aircraft-pa44-seminole folder
check for any .fsarchive or .fspatch files in OneStore that also refer to the pa44 and remove them
restart MSFS
go to Content Manager and re-download the aircraft