Class 'HelixUltimate\Framework\Platform\HTMLOverride' not found

Color me clueless.

I have the J2Store devs looking at their usually bulletproof component; they logged in just a few minutes ago. I'll let you know what they found.

Previously I tried updating to HU v 2 but my header area was completely destroyed so I reverted. I'm not sure if some lingering file may have remained after restoring with Akeeba. I'm experimenting now in a localhost.

If customer is logged in first, the transaction completes. If the visitor is creating an account at checkout, that's when the failure occurs - this points to a javascript or jquery conflict that most likely is something they need to address on their end. Stay tuned.

(Note: I tried copying the site to a new test domain, upgraded to HelixUltimate v2, but none of the navigation works. I get the home page and everything else is 404's.)

I have links working in v2 - I turned off 'follow symlinks' in htaccess. And for the most part, I now have the header (almost) rendering the way it was.

But an odd JQuery error appears in the console, 'Joomla not defined.' I have turned off the Joomla tag in global configs, and I'm not sure whether this item is the cause of the one issue I'm dealing with which is likely caused by the way the cart interacts (or doesn't) with hexultimate. They're working a ticket right now.

See below.

I wonder where that plugin came from? It must have been in conflict with JQuery Easy.

This site goes a long way back and that plugin was last updated eight years ago! One of those legacy things lurking in the background we forget about. The change to J4, when it comes, will surely uncover more monsters hiding under the bed. Thanks for your help.