fatal error

Hi @ sunnygirl123

Once u reupload the theme i think it would work.

Thanks

Hi@ sunnygirl123

If the problem is not solved by reuploading the theme then it may be the version issue,i think u have to upgrade the latest wordpress version.
For futher more info please do visit the link below
https://www.mhthemes.com/support/how-to-fix-add-panel-error-in-customizer/

Thanks

Thank you. I have tried re-uploading but it didn’t fix the issue. I think you’re right tsuzan1, I will need to upgrade to the latest wordpress version
many thanks for your responses

As said by @tsuzan1 , you need to update your WordPress because the older version of the WordPress does not support panels in customizer.