json syntax error receiving

Plugin: 4.2.3
WordPress: 5.1.1 (single)
PHP: 7.0.31
Browser: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.103 Safari/537.36
JavaScript: https://www.mysite.com/wp-content/plugins/redirection/redirection.js
REST API: https://www.mysite.com/wp-json/

Error: Unexpected end of JSON input (SyntaxError)
Action: redirection/v1/setting/ GET
Code: 500 Internal Server Error
Raw: -no data-