Defects Quick Edit - cannot upload attachments.

Since upgrade to 11.8 Saas users are reporting multiple issues:

This one - Defects Quick Edit - cannot upload attachments.

This was working OK for this user prior to the upgrade, since upgrade error is reported.

Can this be investigated please?

Update:

Have retried this method by accessing defect through quick edit - clicking files tab and attempting to upload a file. Even with system admin rights on the project this errors.