I filed my US Resident Foreign Income on a W-2 with no EIN and had ProSeries skip the error checking...

The return was rejected:

Error Detail:
This return could not be processed for e-filing due to incorrect or missing employer EIN or incomplete employer business name.

Error Resolution:
For each W-2, Wage and Tax Statement, verify that the Employee SSN, Employer ID Number (EIN) and Employer Name are entered correctly.

The Employer Name is entered correctly.