Updating failed. The response is not a valid JSON response.

That’s not a specific plugin issue but a generic WordPress error. If you search the www.ads-software.com forums you will find a lot of people having this issue in different scenarios.

I recommend you checking those threads where you will find how people resolved it. You can find also many third-party articles providing tips that could help, here’s one: https://www.wpbeginner.com/wp-tutorials/how-to-fix-the-invalid-json-error-in-wordpress-beginners-guide/

Yes, I know that.
Thanks for super fast reply.
I disabled all plugins and try to activate one by one.
It was this plugin for the cause. When I activate this error happens.

You’re welcome. I have this plugin enabled on multiple sites and I’m not getting any errors.

Are you able to replicate the issue in a clean WordPress installation, with no other plugins enabled and using a default WordPress theme? If so, please provide me step by step instructions on how to replicate the issue in this scenario.

Hi Samuel,
Again, thanks for super fast replies.
It seems my hosting support flagged wrong plugin.
Probably it was the just 1 line above than yours.

Sorry for mistake.