I suspect the error I highlighted in red is only set off when a certain combination of settings are selected or certain things are present in the site or environment. It’s impossible to guess what it might be. It could be something as innocuous seeming as the page name or even just the date.
My guess is that whatever that condition is it’s not something you noticed had changed, but it happened recently and triggered the error.
@yuzool is probably completely unaware of the issue and will likely appreciate the bug report.
Isaiah
I’m away from my Mac for a few hours, but I’d maybe try this tiny modification to that patch?. 
also: Remember to remove this when a real update comes from the stack developer.
#stacks_in_p7_n3_page14 p a {
background-color: rgba(0, 0, 0, 0);
}