Version 62.0b3 (64-bit) (Mac) To reproduce: 1. Go to a website that performs xhr reqs (i.e. https://support.mozilla.org/en-US/questions/new/desktop) 2. CMD + SHIFT + I to open dev tools > Network Tab 3. Either right click on the xhr req and choose edit & resend or one left click then click edit and resend (as shown in screenshot). PS: it works fine in FireFox; iow, it shows a window to modify req then resending it. PSS: can you add a resent option (beside the edit & resend)?? Makes it a lot easier when debugging