Sync errors following 3rd Part Update Publishing

Hi

Having sync'd the updates (Lenovo/HP in my case) and 'published' the updates I wanted, I then got the following errors in the wsycmgr.log:

Generic exception : ImportUpdateFromCatalogSite failed. Arg = 001d4517-c586-4bb1-9e66-ed6ff8e8d34f. Error =The underlying connection was closed: An unexpected error occurred on a send.

[ad infinitum]

I can't seem to find any reference for this anywhere so hopefully someone can help out. It's a lab machine with no proxy restrictions, etc but I'm running as a test before going to prod so don't want to run into the same issue there where it'll take much longer to sort out any issues.  Have attached log.

Thanks