EMFILE: too many open files (Heavily edited!)

When I attempt to run my app today  in VSC, it's failing with:

EMFILE: too many open files, open '/Users/alansmith/Library/Application Support/Garmin/ConnectIQ/current-sdk.cfg'

That opens a file containing the text:

/Users/[my user name]/Library/Application Support/Garmin/ConnectIQ/Sdks/connectiq-sdk-mac-7.3.0-2024-08-27-36488f6f5/
The folder "Sdks" does exists OK

When I attempt to open the SDK manager from VSC I get :

It looks  like the SDK Manager has become corrupted.

A couple of hours later I returned to the problem and tried opening the SDK Manager it commenced an update:

during which a number of warnings appeared in VSC:

plus similar ones for each of the Fenix8 models.

On completion it displayed:

On returning to VSC, manifest still appears in red and , despite restarting VSC,  a build of my app still returns the original error:

and once again Open SDK Manager fails with:

The Sdk folder looks fine:

Any suggestions to get out of this impasse?

Apologies if you have been seeing the real-time edits to this post, but I'm calling it as it unfolds.