I also did the steps in the following post but it did not work for me. https://www.joomshaper.com/forum/question/5735https://www.joomshaper.com/forum/question/5735

I also don't have advanced template manager installed. I don't understand where the conflict/issue is. I had helix/sppb pro working well on a cloned copy of my live site but now when I try to set it up on the live site it will not work. I really need help in getting this sorted!

Hi there,

Thanks for contacting us. Sorry for the inconvenience. Will you please provide me the Joomla administrator access to check the issue? I will check & get back to you soon. 

-Thanks

Okay, I added it. I was able to still use the layout by copying the information from the staging site to the live but I still cannot see the template and get the same error.

I think this problem occurred for the third party extensions. Please download a backup of your site & disable the third party extensions one by one and check again. Thanks

I wondered that, but it works on the cloned site, which is an exact copy with the same extensions.

Maybe, something was wrong when you have installed the Helix. You can continue with the copied template. Cause, everything is same on copy template. Thanks

I just disabled the animation on the site header to try and improve page speed, and voila - I can see the template editor again. I am not sure if that was the issue - I just thought I would post in case it can help anyone else.

Thanks