Symptoms

Unable to submit order guide after the upgrade. 

Release

London

Cause

This is the expected behavior in London release. The old behavior, where you could have inactive items added to the cart, was identified as not being the correct one and has been fixed 

Resolution

Activate the catalog items associated in the Order guide 
Make it active and it works as expected. 
This is the behavior change in London and going forward catalog items should be active.