When I try to download the grader app, I get this message saying that the app can't be upgraded.
Yeah, sorry Salesforce doesn't give a clear message but it means it's already installed. You can't install it again when it's already installed - it thinks you're trying to upgrade. You only install it once for grading all labs.
Yeah, sorry Salesforce doesn't give a clear message but it means it's already installed. You can't install it again when it's already installed - it thinks you're trying to upgrade. You only install it once for grading all labs.