It sounds like you need to check with an administrator of your PressRun account to check you have 'designer' access to the publication you are working on. Please get one of your PressRun administrators to log in to my.pressrun.com, go to the organization screen and enable the designer role for all publications you need to access and upload files to. Additionally, ensure you PressRun account does not have both 'Tester' and 'Designer' access. If you need to upload you need 'Designer' access which gives you the same testing capabilities of a 'Tester'. Having the two roles on the same user account causes a conflict of access rights.