User-Agent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:188.8.131.52) Gecko/20060111 Firefox/184.108.40.206 Build Identifier: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:220.127.116.11) Gecko/20060111 Firefox/18.104.22.168 I started Firefox, the last session was opened (thanks to the Tab Mix Plus extension), then every tab reload was blocked. I noticed after closing the main Firefox window that there was a "Server Certificate Expired" dialog below it (it was complete hidden). It usually appears above the main window. Since this dialog blocks everything, Firefox should probably make sure that it always appears above the main window, making it reappear above if for some reason it is opened below. Otherwise this is very confusing. Reproducible: Couldn't Reproduce Steps to Reproduce:
(In reply to comment #0) > Since this dialog blocks everything,<..> This part seems to be (Firefox bug 251624 ->) bug 74331.
The security code uses the "modal" parameter to open the "cert expired" dialog. If Firefox opens that dialog behind the main application window, it's not a bug in security code, but in global UI code, I think. See nsNSSDialogHelper.cpp kDefaultOpenWindowParam contains "modal".
I've updated the summary: First I removed "all connections blocked" since this is another bug (comment #2). Then I now know what happens (and this is probably what happened the first time, though I don't remember exactly). When starting an application, Mac OS X sometimes makes the windows appear below the windows of the current application, so that the focus is not stolen, AFAIK. As a consequence, the main window of Firefox may be partly visible and the "Server Certificate Expired" dialog may be completely invisible (entirely behind a window of the other application). And after I clicked on the Firefox main window, the SCE dialog was still hidden. Firefox should do something about this problem, to make sure that the user can see the SCE dialog. Note: as an example of webpage that makes the SCE dialog appear: https://admin.opendarwin.org/
Same behavior when selecting Firefox with Cmd-Tab instead of clicking on its main window.