Thank you for briging the issue to our attention. I am checking into this with some of the team members at Tableau to determine if they have any tips to share.
My best guess is that the problem has to do with some incompatibilities between the browser Tableau uses (QT WebKit), and a modern web browser that you are using to run the simulator (chrome for example).
Hard to say from that error message though. When you say the debugger crashes, when does that happen? It is actually expected to "crash". By that I mean, the window should become unresponsive (and Windows may prompt you to close the window), while you are performing operations in Tableau. This is because the debugger only attaches to a background process when the getData phase is running. So it'll be active when your connector is returning the schema, become inactive while users are creating tables/joins in Tableau, and then activate again when your connector is performing the data fetch.
You can also take a look at the logs to see if there is more info.
If the above doesn't help, I'd be happy to help troubleshoot if you want to get in contact with me offline with a test sandbox api key (email@example.com).