I have the same problem with the project not being allowed to be deleted. I have run the unbilled time/costs report and there are no outstanding items. The message I get says "To delete this project, please ensure there are no time entries linked to it first.". I can't really believe that QBO expects me to delete all the time that has ever been applied to this project just because I'm finished with the project and or the client. I also tried using the incognito window with no change. Please help!