I build a WF to return user error when some custom date field in the invoice does not meet the requirements. It must work in Edit mode while in a record and also using inline edit mode while you are in the list. Everything works fine if I test it in Sandbox. However it fails (partially) in PROD environment. By saying partially I mean that it doesn't work as expected in inline edit mode. When user enters wrong value, system shows no pop up message about the error, but if you reload the page with invoice list it appears that value is not saved and that is a correct behavior. So in fact only pop-up message and field cleaning are missing. What can be wrong?