Symptoms
When loading the guided tour in designer, the steps are missing on the right under the callouts. There is also an error in the console debugger:
Uncaught SyntaxError: Unexpected token X in JSON at position X
Cause
The JSON is attempting to parse a non JSON object. If you breakpoint the JSON parse, you will find there may be a sentence instead of JSON. This is due to having the short description placed in the option's field.
Resolution
Ensure the short description is in the short description field. If the options field is filled with a string, it will break the guided tours steps parsing before it finishes loading.