Hello I’m sorry you’re having this problem.
Not able to reproduce this issue with the main theme, or with the child-theme (provided on presscustomizr.com).
You say the issue occurs only with the child-theme right?
So probably the issue is in *your own* child-theme.
Looking at the link you provided about the “syntax error” (https://stackoverflow.com/questions/23511275/json-response-format-error-red-dot-bullet-before-response) you can see that the most reliable reason is (might be):
It was probably a file encoding problem caused by editing the files on the remote end with notepad. I’ve re-uploaded the files from the localhost and it was solved.
Windows Notepad adds BOM information to UTF-8 files (i.e. FFFE or FEFF at the beginning of the file) which would explain this behavior. In Notepad++ for example you can prevent UTF-8 from including BOM information using the “Format” menu
and so on.
I searched files presenting BOM in the theme and couldn’t find them.
(in a linux shell, in the theme root dir: grep -rlI $'\xEF\xBB\xBF' .
)
Though I downloaded *your* child-theme style.css
(https://www.eatgafftaperadio.com/wp-content/themes/customizr-child/style.css)
and found that it actually has that BOM. I can only wonder that your child-theme functions.php has that too.
Did you edit those files with notepad++?
Probably that editing introduced the issue.
You might try building a new “vanilla” child-theme and see if it still happens (or download the provided child-theme again).
And if you want to edit its files be sure that you’re encoding them with utf8 without BOM (always in the link you provided there’s a way to do that if you’re using notepad++).
As per wp.org forum rules direct contacts are not allowed as the themes/plugins hosted, and the forum itself, are free, so the presscustomizr team cannot do much more to debug your particular issue, which as you said doesn’t happen with the main theme.
Hope this helps, and you can solve it.
Best regards.