ERROR: SyntaxError: Unexpected token '<', "<!DOCTYPE "... is not valid JSON

Problem/Motivation

When the configuration is not quite right, and you try to connect to the mcp, you are greeted with an error that isn't helpful or explains what needs to be done to fix. You get:

ERROR: SyntaxError: Unexpected token '<', "<!DOCTYPE "... is not valid JSON

Which likely is received because the app is expecting to receive JSON and not HTML. This is a difficult error to recover from because it isn't clear what the next steps should be:

• Should you delete the docker instance and pull a new one?
• Should you fix your configuration (likely in the local .mcp.json file)?
• Should you reboot to allow the instance to restart?
• Should you attempt to recreate the docker command outside of the context of mcp installation?

Please advise and improve error handling.