Missing Startup progs after WU

After last night's WU to 1803 build 17134.648 several of my startup
programs are not loading.

I ran Nirsoft's AutoRuns and these missing programs were now showing
with .lnk file entries, instead of .exe like most of the hundreds of
other entries.

Also: while in AutoRuns I saved the .arn file as a precaution and
deleted a few entries which seemed identical duplicates. After a PC
restart the missing progs were still missing. I re-loaded my .arn file.
On then looking in my Startup folders, which probably had around ten
entries, to my dismay I found they were all missing.

I'm about to search for backups of
C:\ProgramData\Microsoft\Windows\Start Menu
and
C:\Users\terry\AppData\Roaming\Microsoft\Windows\S tart Menu
but meanwhile any insights please?

Terry, UK