By definition, your "custom" would be different than my "custom".

In other words: I don't even have a clue what I would need to do in order to try this on my own installation. If you're really looking for an answer: Consider to provide some information on what you do, experience, expect etc.

Apologize not provide in details:

1. This is when creating a New Custom Object on App Builder (Control Panel > Applications > App Builder > Objects)
2. I have two error messages when access the home of Objects page (pic. 1) and when submit new name of Custom Object (pic.2)

Pic-1 (Error:An unexpected error occurred.)

Pic-2 (Error:Unexpected token < in JSON at position 38)

I hope this additional information can clarify my question. Thank you.