Steps to reproduce: Create a character wearing 'Scrub Pants' and try and export the character to USD.

The message shown says 'The following content item is not listed in the Marketplace yet'.

I had to delete every element in my scene until I determine the missing item was on the character.

Then I had to delete all the characters objects one at a time until I narrowed it down the Scrub Pants.

It would save a lot of time if the message listed the missing items.

Thanks