Unable to Save Changes

One thing that annoys me about HookTheory is some of the melody lines won’t let you save any changes or corrections you make. I’ve created tabs for many songs on this website that were not here when I first started. But, in some projects where I see a need to make corrections, I hit submit to publish my changes and it gives me this error message: “There was an error with the server. (HTTP Status 500)”. Can you explain what this is and how it can be fixed?