User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:42.0) Gecko/20100101 Firefox/42.0 Build ID: 20150921004016 Steps to reproduce: Type "firefox developer edition" in address bar. Actual results: Contextual content position is off. I get similar issue by clicking the hamburger menu of Firefox and the popup is very far away on the left (almost middle of my screen). Impossible to take a screenshot because moving away makes it disappear. Expected results: Contextual content should be position relatively to the field.

Sorry for the phone picture but I couldn't take a screenshot. I get this on Linux and OSX.

I have experienced the same issue after updating to Firefox 43 on Linux. Here's what I've observed: 1. Start Firefox and bring up the suggestion box by typing in the location bar. The suggestion box will display correctly each time you bring it up. 2. Move the Firefox window. If you open the suggestion box again, it will once again display correctly. 3. Close the suggestion box and bring it back up again. It will show up at the location it was in based on the original position of the window. Each time you move the Firefox window, the display box will show up correctly once. Every time afterwards, it will display at the original location of the window until you move the window again.

This bug seems to affect the location bar, search bar, and suggestions for input fields. (e.g. username field for a website's login) This has occurred on multiple machines running Linux, both when running with one or two monitors. Multiple monitors is more annoying, though, since oftentimes the menu will appear on the other monitor.