Joomlart prevents theme change?

uriel29

My client has a Joomlart themed site.
But when I move to Helix.

The site does not change. When you disable the Joomlart theme
From error> Class 'JATemplateHelper' not found

We do not want to use the Joomlart theme anymore.

Why stop me from changing?
Are you forcing me to use it?

pavit

If you want to use a helix based template then you can uninstall any joomlart extension installed like the T3 framework plugin , nobody stop nothing here

Regards