Thank you Matt, I will take this info to my team and review the WWDC video

Hi Matt - so digging a bit deeper, I'm seeing that adding: let contentController = WKUserContentController() contentController.addUserScript(...) allows this all to work (makes sense, given the suggestion in the exception message) We're still checking on our end how Apple Pay APIs would be available, as this code has been working untouched until recently. (we don't even have Apple Pay enabled for our domain - no merchant IDs, no environments setup) As far as I understand it, it is functionally provided by the browser - but unsure how or why this has recently become an issue. (we're seeing 300k+ users affected, over 10M exceptions this month)

Just following up here with some closure - it appears to be that one of our 3rd party vendors silently enabled something that causes Apple Pay to be detected on the page. We've blocked this library on our end for WKWebview loads, and our pages are behaving as they were.