Getting Syntaxerror: Unexpected End Of Json Input With All Addons

I've just moved my store which was working on an IP address to a new domain, I've cleared all the var cache and the site now loads. However I'm not getting the error:

syntaxerror: unexpected end of json input

Both on the admin side when I try and edit an addon and the front end side when it calls upon an addon (the product configurator)

Everything was working fine until the domain name change, what could cause this and how to fix it?

The addon you describe probably is not intended for the new version, uninstall it

No it's all addons and the template page in the admin login. The product configurator addon was customised for us and working up until the domain name change, this is the only thing that changed between working/not working.

have you added the domain name in admin>stores

https://prnt.sc/j7unps

Yes

get in touch with CS cart support may be the only option, investigate on server

or the addon developer

I've taken out a support ticket, I'll report back what we find

Have your hosting verify that all file/directory ownerships/permissions are correct for your new environment.

Have you tried to access your site with a browser inspector opened? You can look at the 'repsone' and will probably see a PHP error or smarty error. Is there anything in your php error_log file?