According to the conditions of the ERC Consolidator Grant 2017 call, as long as no PhD document or equivalent is uploaded in the Participant Portal Submission Service (PPSS), it will not be possible to validate/submit the proposal. A warning message will inform the applicant of the missing document. If another document is uploaded instead and the PhD certificate is finally missing in the proposal, the proposal is not eligible and will not be evaluated.
For more information, see section 'Eligibility criteria' of the ERC Work Programme 2017.