updates page shows an error for a mystery module 'standard 8.6.12' on the updates page /admin/reports/updates under Modules there is a module called standard 8.6.12 as and it is highlighted with a warning No available releases found (Warning) 

this module does not appear when running $ composer outdated

is there any idea where this module is coming from, if it is in fact needing an update, or if this is just a typo in one of the site's config files somewhere?

this is what I see:


I have recently updated to Drupal 8.6.12 (using $ composer update)
going to mark this as answered so I can close it...

I removed a contrib module that we are no longer using and the mystery module "standard 8.6.12" no longer appears.

I cannot say for certain which module it was - but I am 99.78% certain it was from a contrib module, not from a core one.