User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.112 Safari/537.36 Steps to reproduce: 1. Open the about:debugging page. 2. Make sure the "Enable add-on debugging" box is checked. 3. Click the "Debug" button next to my add-on's entry. Actual results: The debug popup opens, but there is no content (no matter how long I wait). It seems there is something wrong with the debugger. Expected results: The debugger can be used and it can show me some detail information or errors about my add-on.

Sorry, I submitted using Chrome, so the User Agent above can't help. I can reproduce the bug on the newest Firefox Developer Edition, and its User Agent is 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:47.0) Gecko/20100101 Firefox/47.0'. Thanks.

Did you get an "Incoming connection" popup after clicking on the Debug button ? (see https://www.youtube.com/watch?v=tGGcA3bT3VA as a reference to what "should" happen). The empty popup you see usually means the browser toolbox is not connected to the browser yet. Does this happen only with your addon or with any addon?

After clicking the Debug button, the "Incoming connection" didn't popup. Instead, there was only a complete empty screen popuped as the attachment (https://bugzilla.mozilla.org/attachment.cgi?id=8742673). It happened to all the addon including the Firefox Hello you provided.

Hi Wei Qi, thank you for reporting this bug! I'm not able to reproduce it on Windows, however the Browser Toolbox window sometimes takes too long to open on first launch, timing out before the "Incoming connection" screen has time to show up. 1. Does the Browser Console show any errors? (You can find it the Firefox menu, under "Web Developer" (Wrench icon), at "Browser Console"; or maybe even with the right "1" in bottom right of your screenshot?) [0] 2. Does the problem reproduce if you close the empty window, then click the Debug button a second time? 3. In about:config, are both prefs "devtools.chrome.enabled" and "devtools.debugger.remote-enabled" set to `true`? [0] https://developer.mozilla.org/en/docs/Tools/Browser_Console

It's strange. I can reproduce it at Windows 10 and Mac OS 11 with the newest Firefox Developer Edition(47.0a2) and the Firefox Nightly. I couldn't see any "Incoming connection" screen no matter how long I waited. For your questions: 1. Yes, Browser Console would show some errors as this screenshot (https://bugzilla.mozilla.org/attachment.cgi?id=8743852) when I opened my browser from Terminal as the instruction you provided. More importantly, whenever I clicked the debug button, there was a confirmed error which was showed at Terminal (JavaScript error: resource://gre/modules/XPCOMUtils.jsm, line 191: TypeError: can't redefine non-configurable property "Services"). I have already downloaded the XPCOMUtils.jsm and uploaded it to the attachment (https://bugzilla.mozilla.org/attachment.cgi?id=8743858). The screenshot of line 19 is: https://bugzilla.mozilla.org/attachment.cgi?id=8743855. I think this is the main cause of the bug. 2. Yes, the problem can be reproduced. 3. Yes, both the prefs are set to be 'true' (the default value has already been 'true'). Many thanks. It would be highly appreciated if this bug could be fixed ASAP.

Thank you for replying with additional details, they're especially helpful because we can't reproduce the problem on our side. (In reply to Wei Qi from comment #8) > It's strange. I can reproduce it at Windows 10 and Mac OS 11 with the newest > Firefox Developer Edition(47.0a2) and the Firefox Nightly. I couldn't see > any "Incoming connection" screen no matter how long I waited. I'm still not able to reproduce (for me it works as expected, or at least the second time I click on the same "Debug" button). - Does the bug still reproduce if you set the "devtools.debugger.prompt-connection" pref to "false"? (This will bypass the "Incoming Connection" confirmation screen). > More importantly, > whenever I clicked the debug button, there was a confirmed error which was > showed at Terminal (JavaScript error: resource://gre/modules/XPCOMUtils.jsm, > line 191: TypeError: can't redefine non-configurable property "Services"). This looks a lot like bug 1222998, and you're probably right about it being the root cause here. Alex, do you know who we should ping to get bug 1222998 resolved?

The debugger screen can show content if I set the "devtools.debugger.prompt-connection" to "true". Then the error at line 191 also disappear. Thanks.

(In reply to Jan Keromnes [:janx] from comment #9) > > More importantly, > > whenever I clicked the debug button, there was a confirmed error which was > > showed at Terminal (JavaScript error: resource://gre/modules/XPCOMUtils.jsm, > > line 191: TypeError: can't redefine non-configurable property "Services"). > > This looks a lot like bug 1222998, and you're probably right about it being > the root cause here. I don't think this error message is related to this breakage. We always see this error message, even on working browser/addon toolbox. > Alex, do you know who we should ping to get bug 1222998 resolved? No. I tried to figure this out without success. May be :jryans. But given that this exception happens only in the browser toolbox and doesn't seem to break anything, this isn't getting much traction. Given that the problem disappear when we disable the prompt, it is more likely to be related to it. Wei, I know that sometimes the "incoming connection" popup hides behind the debugger screen or the browser window. Could you triple check that it isn't hidden like that by trying to minimize all the opened windows/popup? Otherwise, I imagine the popup is just broken for some reason. Do you have any particular addon installed? Or any particular setup on your Mac regarding Windows/Dialog behavior?

(In reply to Alexandre Poirot [:ochameau] from comment #11) > I don't think this error message is related to this breakage. We always see > this error message, even on working browser/addon toolbox. In that case I'm dropping the dependency on bug 1222998. > Given that the problem disappear when we disable the prompt, it is more > likely to be related to it. > > Wei, I know that sometimes the "incoming connection" popup hides behind the > debugger screen or the browser window. Could you triple check that it isn't > hidden like that by trying to minimize all the opened windows/popup? > Otherwise, I imagine the popup is just broken for some reason. Do you have > any particular addon installed? Or any particular setup on your Mac > regarding Windows/Dialog behavior? Needinfo Wei Qi about these questions.

Hi Wei Qi, does this bug still reproduce on your side? If so, could you please have a look at Alex's questions in comment 11? If the problem doesn't reproduce for you anymore, we can close this bug for now.

(In reply to Jan Keromnes [:janx] from comment #13) > Hi Wei Qi, does this bug still reproduce on your side? If so, could you > please have a look at Alex's questions in comment 11? > > If the problem doesn't reproduce for you anymore, we can close this bug for > now. Sorry, I've just seen Alex's comment. It's very confirmed there was no "incoming connection" popup hides behind the debugger screen or browser. I had checked it for several times. But for now, when I change to a new MacbookPro, the problem can not be reproduced anymore. It may be my old computer's environment problems. Thank you Jan, you can close this for now.

Thank you Wei Qi! Closing for now, as we are not able to reproduce the issue. If someone else encounters this problem again, please re-open this bug, and please provide any details that could help us reproduce the same problem on our side.

[Exception... "Component returned failure code: 0x804b0014 (NS_ERROR_NET_RESET) [nsIInputStream.available]" nsresult: "0x804b0014 (NS_ERROR_NET_RESET)" location: "JS frame :: resource://gre/modules/commonjs/toolkit/loader.js -> resource://devtools/shared/security/socket.js :: onInputStreamReady :: line 298" data: no] I am getting the above error on some of the window machines (tried with windows 10 & windows server 2012 R2) on opening browser toolbox. This issue does not reproduce on all the machines. This issue really hampers my developer experience as i am not able to use dev boxes for developing extensions on firefox. This issue can be seen on latest releases firefox (firefox 50 beta) as well as on nightly builds. Please note that this issue is happening continuously for me. I have tried all sort of workarounds like restarting the machine, trying opening browser console multiple times, restarting browser. I am just not able to use browser console on some of the windows machines. Any help in this regard would be highly appreciated. As mentioned in the bug, incoming connection popup does appear on some of the windows boxes. It is very hard to reproduce it as the issue does not happen on all window boxes. However, on whichever box issue happens, it happens consistently.

I would be happy to enable any logging on my firefox browser and give it you folks for debugging. I believe we should debug such inconsistent issues via logs. Asking for reproduction steps does not help always especially in cases like this.