Quote Originally Posted by Nick1973 View Post
I'm getting the 'Sorry, but our expedited checkout process cannot be used' flash up for a millisecond then it disappears. It appears that orders can still be processed though. I am using Zen Cart 1.5.7c, Bootstrap 4 and the OPC Styles for Bootstrap 4. Jquery is on 3.5.1. It only appears to happen on a Desktop. It's just a very quick flash.
That's the way that OPC is designed. That "Sorry ..." message shows initially, until all the page's javascript is loaded and the OPC jQuery turns that message off.

It's the only way I could think of to give customers an opportunity to still checkout if the site has a javascript/jQuery issue during the page's load ... which will cause OPC's jQuery (which is an integral part of the processing) to not work.