The Malwarebytes Browser Guard Extension (Chrome or Firefox) does not work with Orion RC Version 0.99.124.4.4-rc (WebKit 6184.108.40.206.1) but does work with Version 0.99.124.4.1-beta (WebKit 6220.127.116.11.1).
WIth the RC, clicking the extension on any given page results in, "Orion can't open this page. This operation could not be completed (Orion_RC.SchemeHandlerError error 2). Attempting a reload doesn't fix.
With the current Orion beta, the extension works perfectly.