I am having strange issues with extractors - I can't get any regular expressions to work, including included ones such as email address and others I've tested with regex101. I also cannot extract an email subject - it only will pick it up by using After with Attachments, etc., which won't pick up all cases.
Is there anyone out there that is having these kinds of problems that could help me? I tested Syntex with classifiers with good luck but bombing out on a lot of extractors that really should work.
Are you getting an error message on the page when trying to save the RegEx? In the F12 debug logs of the browser, are there any error messages? There are some expressions that are not supported by LUIS, but you'll get an error message when trying to save the page.