We have compiled our site compatibility notes for Firefox 68, which is currently on the Beta channel and shipping on July 9. As you can see, there are some changes to
XMLHttpRequest among others. Enterprise app developers should be aware that Firefox 68 is the next Extended Support Release (ESR) but service workers and push notifications will be disabled as with the previous ESRs.
Let us know if you notice any other issues! We’ll soon start working on Firefox 69 compatibility notes as well.