I haven't worked on that particular installation since then, but I will later today. I'll double check then.
I just took a look at one of the live sites I run the plugin on, with current live version 3.0.13. I don't get the error (presumably because I don't have debug turned on on the live site), but what I'm seeing is effectively the same at the interface level.
If you have an existing job and click on Edit under the job in the list, what you get is an interface panel where the General tab is not selected. In fact, none of the tabs are. You just see a list of tabs and the Save changes button. Clicking one of the tabs then brings that tabs options up.
I'll get more details under the debug enabled dev site this afternoon and create a github issue from them.