Hi Behavior: Blue squiggles appear on screen as I type in textboxes. Secondary Behavior (could be related or unrelated): Checkbox graphic is not appearing on web page. The text to the checkbox is appearing. So I cannot check the checkbox without the graphic. How do I troubleshoot the root cause of this new behavior I am observing in Fx? What is this behavior actually telling me? Fx39/Yosemite 10.10.3/MBP Background I have seen this behavior before in an older version of firefox and when I was on Mavericks OSX, and it took fresh install of Yosemite (and a brand new profile of Firefox) for it to go away. That was like a year ago. A year ago it appeared when I was trialling proxy addons, exploring options. Current This week, I am observing, intermittently, as I type in text box in Fx, sort blue squiggles appear. It does not impeded typing. - It makes no different if I have hardware acceleration off/on in my Firefox settings - Both these behaviors go away IF I turn ZenMate addon totally OFF (e.g. proxy off and smart locations off). It could be ZenMate has caused it as since I installed that add-on my fx in general has declined and this behavior started on the new install. But I cannoto be sure it is ZenMate as the behavior is intermittent when using it. ZenMate support have not been helpful at all, so now I am seeking to understand what does this behavior in general tell me. Thankyou for your time.