Firefox freezes after trying to open "Downloads"




Recently installed MATE 17.04 - clean install on an X220/i5/16GB RAM/250 GB SSD.

My problem is as follows.

When Downloading a (any type) file using Firefox 52.01, when the file download concludes, if you click on the little “display progress of download” arrow on the address bar (RHS), then click on “Open Containing folder” my machine crashes. It sometimes becomes responsive after a minute or 2, sometimes all I can do is bring up a terminal (which is basically all I can do - all menu’s are unresponsive, as is FF, shutdown button, anything in the panel, etc.) search for the PID of FF and kill it.

I have tried:

  1. deleting FF and old profile I had copied across from my old O.S (16.10 Ubuntu Mate) and reinstalled a new copy of FF - via the Package Manager , which created a new profile. No addons or extensions applied.

  2. Disabled everything. Ran FF in safe mode, refreshed FF, reset the browser:download user settings. Still same problem.

  3. Cleared cache, cookies, etc on new fresh FF install.

  4. I have just tried booting 17.04 using a bootable USB drive (ie. running Ubuntu 17.04 Mate from a USB drive) on the same machine. The problem is still present.

5 . I have tried again to change my download location to another newly created folder in my /home directory. The Problem is still present.

  1. Whilst testing FF, I ran “htop” from the command line to see if there was a memory issue. The Firefox PID was only reporting ~2% of CPU & ~1.5% of RAM. I did notice however that whilst FF was crashed, several processes (new PID’s) were being created. Not sure if that’s relevant.

  2. Other programs on my system quite happily let me save and choose a folder to save to.

8 . PDF’s opened via the browser PDF application (Atril) work fine. But if that PDF is Downloaded, and the Download arrow is clicked after D/L completion, then the folder icon to open file location - it crashes.

  1. I have also tried FF 51 on same machine, and get same thing/problem.

Initially I thought it a FF problem and have submitted this:

But, on further investigation I don’t think it’s FF crashing as I don’t have anything in “about:crashes” in FF.

I have also subsequently gone back to 16.10 (used another SSD) and have no problem with FF and D/L’s.

I am really thinking it’s a MATE problem.

How can I go finding out exactly what is crashing? It’s like the MATE desktop is crashing (I think) …Any other thoughts? Diagnostics I can run?



(excuse numbering, it kinda got wonky after I posted, can’t fix for some reason…)


Others have reported a similar issue. See -


Sorry for my bad English. I have a same issue here on Ubuntu mate 17.04. When i click on Same here. When i want to open the Download locationб Firefox freezesб but about 10 sec. or soб opening files, but not in file manager, but in audacious music player…


Created bug report.

Please add any other information, etc.




Today i tested Solus MATE 2017.04.18 with Mate Desktop 1.18.0.
There Firefox also freezes when trying to open “Downloads” after downloading a file. I added this text also to bugs.launchpad.
Just to let you know :slight_smile:


This is now fixed:

Sorry, that was a regression from migrating Caja to GtkApplication in 1.18. We’ll release a new 1.18.x version later.
@Wimpy: please pick up the patch :slight_smile:


Thanks for fixing it, and thanks for posting here to let us know!


Can someone please tell me how to implement this fix step by step. I have no idea what to do with the code very new to linux. Thanks so much.


I don’t understand why you don’t update Caja? Why this is still not fixed? It is so annoying to work, open Downloads in Firefox and then the whole system freezes. These sort of things show which Linux distributions you can rely on and it doesn’t look good for Ubuntu Mate.


I understand your trouble. It’s also annoying for me. But my “workaround” is to open the Downloads-Folder direct in Caja. You have to know, Ubuntu MATE 17.04 is “only” a Short Term Support Version. For a stable version you should use 16.04. But i agree, it’s irritating. Further there seems to be a fix for this which is not available


I would understand if there would be bugs, and the staff would investigate and they wouldn’t be able to provide a solution. But to have a bug that can freeze the system, and then, luckily, come up with a fix that works, but chose to not deliver it through the update system, it’s so strange for me.
Why would they fix a bug if they don’t intend to share it with the world?!?!?! I bet there are users out there that experienced the bug and have no idea about this topic. Maybe they think that Ubuntu Mate is not stable, and that it randomly crashes. They would be right to think that. Except that it isn’t random, the developers know why it happens, but they refuse to fix it for the non-tech users.
For me, this attitude is so disappointing.

@Etamuk, I know 17.04 is a Short Term Support Version, but it is still in support. It’s the latest version, and it is supposed to be stable. Which it isn’t for the most users that click on Downloads in Firefox.


I would like to remind you, @xandor, that fixing bugs takes time.
The bug is now fixed upstream in caja version 1.18.3.
In order for an update to make it into Ubuntu MATE 17.04, it has to first undergo the Stable Release Update process. Furthermore because Ubuntu is based off of Debian, there might be another layer to go through before an update can reach Ubuntu.
Please stop assuming stuff like:


I would further remind you that our leader has a life, including a family, and that maintaining Ubuntu MATE is not his job. It is something he does in his free time for no profit.


From my point of view, this is not a regular bug. This is a critical bug, and in my mind that means that these kind of bugs would be fixed much faster. Firefox is the default browser in Ubuntu Mate, and if users click on Downloads, the system would freeze. The bug has been confirmed and a solution now exists. But not for me + most of the other users. I guess, if I forget, and click downloads, I should just get used with the system freeze. But hey, it seems that I don’t get it, and the proper way to deal with this, is just accept the freezes.

So you are implying that the project depends on only one person? Of course is normal if he doesn’t have time, but I would think that other people would have to deal with the critical bugs when the main developer can’t.


[quote=“xandor, post:27, topic:12630”]This is a critical bug, and in my mind that means that these kind of bugs would be fixed much faster.[/quote]Personally, I feel you’re kind of driving the point home a bit excessively. Yes, it is a severe bug but it is not that critical.

First of all, there is a very simple workaround. Secondly, Firefox may be the default browser but it is far from the most used browser. Firefox’s day in the spotlight has come… and gone. Servo (the new backend in development by Mozilla) might see it return to that spotlight. Eventually.

The fact it is default mostly has to do with the license and development model of Firefox.

And lastly, bugs do take time to fix. It has been said before but it is not something you should ignore. Take the recent WannaCrypt outbreak for example. That used an exploit in the Windows operating system to spread itself. It was fixed but not before the outbreak actually was able to do some damage.
And there we’re talking about Microsoft. A massive commercial entity whose influence actually outreaches a great number of countries. And even in that case it still took time. And the bug/exploit in question was far, far, far more severe. This crashbug in FF isn’t going to create the next WannaCrypt outbreak. It is just going to annoy a few users, nothing more.

Patience is a virtue and with a very easy workaround available to you, I would personally find it embarassing to exaggerate the severity of this situation.


I have no idea how to fix it. It wouldn’t be wise to asume that everyone is experienced in Linux and have the same tech level. Am I alone? Look at @figarow in this thread, what was your response guys? You ignored him.

This is true when it comes to Win and Mac. On Linux, Firefox is still probably the most used browser. [quote=“1Q7FE6zp, post:28, topic:12630”]
And lastly, bugs do take time to fix.

I understand that it takes time to fix bugs, but once a fix has been developed, it would make sense to see it implemented through the official channels. Yeah, WannaCrypt was more dangerous, but it was fixed asap once a solution was found. In the firefox case, the bug has been fixed 21 days ago, but still hasn’t been delivered through the update system.

A severe bug, for me, it would be when only an app would be affected. But when the whole system is not responding anymore, I would think this is a really serious issue, and should be treated as a critical bug.
" I can’t use my laptop anymore, but hey, it’s just a regular bug, don’t worry. I feel much better now, mate. Thanks for the support."

Indeed patience is a virtue, but it would be stupid to think it applies to all situations.


This is true when it comes to Win and Mac. On Linux, Firefox is still probably the most used browser.[/quote]Given the incredibly low market share globally, I’d say – Probably not.

See:[quote=“xandor, post:29, topic:12630”]
Yeah, WannaCrypt was more dangerous, but it was fixed asap once a solution was found. In the firefox case, the bug has been fixed 21 days ago, but still hasn’t been delivered through the update system.[/quote]Unlike the team behind the MATE desktop, behind Ubuntu, Microsoft actually has far more money and far, far more influence. And, far more responsibility. For Microsoft it was incredibly important that a fix be implemented and released as soon as possible. For Ubuntu (MATE or otherwise), fixing and releasing this bug isn’t on the highest tier of importance. Nor should it be. There literally are more important matters that might take precedence. Do not ask for examples, please. You’re still exaggerating the severity of this situation. Greatly exaggerating it.[quote=“xandor, post:29, topic:12630”]
Indeed patience is a virtue, but it would be stupid to think it applies to all situations.[/quote]I don’t even know how to respond to this without sounding like a total jerk. But I’ll try – In ANY situation patience is a virtue. Both in real life as well as online and even in software. Why in software? We create the software, we humans that is. As such, we create the bugs. Want to know a common cause for bugs? Haste. Being a gamer I can guarantee you this much. Assassin’s Creed: Unity, anyone? That one was released well before it actually had seen rigorous Q&A. Because the shareholders were impatient. And the consequence? A product that single handedly killed the franchise.

And being a married man, I can assure you that even in real life and in a relationship, patience is a virtue. And having been the victim of nasty, possibly life threatening incidents and complications I can tell you – even THEN patience is a virtue. This one time I literally had to crawl for 8 hours to reach a phone to save my own life. Impatience might’ve made me give up.

Patience is ALWAYS a virtue.


Yeah, Ubuntu Mate has limited resources, and therefore, they can fix fast only important bugs. I’m glad that they are not wasting their time for fixing a bug that only crashes the system. I mean, people should just continue to use their OS even when it isn’t responding anymore. No big deal. I applaud Ubuntu Mate’s determination to provide excellent support.

I started using Ubuntu Mate after it became an official Ubuntu flavor. I considered that they would have access to more resources and they would be able to offer better support and I was happy with the OS until now. For me, this is clearly a bug that should be fixed fast once there is a solution. I guess I had the wrong expectations about this distribution.

But it took action to crawl to reach a phone. It would of been much easier to wait, to be patient hoping for the best. I’m glad that you choose to do something instead of be patient.

In the end, I will fix this bug by changing the distribution. It’s not just about this bug, but the attitude: “Just don’t click on that button and open the folder manually”. It seems that Ubuntu Mate is focused more on good workarounds instead of providing a stable system.

It’s also a question of responsibility. Mistakes can happen, we are all humans, but once we commit errors, the proper response shouldn’t be to correct them?


Hi All,

Just thought I’d my 2 cents as this bug has been affecting me quite a bit. I can’t count the number of times I’ve accidentally frozen my system now. My usual way of working is to click show in folder in Firefox after a download. It takes a fair bit of re-training to change a habit of many years, so I don’t think the workaround is really all that fantastic. If it was something as simple as a Firefox crash, leaving the system responsive then it wouldn’t be much of a deal. But here we a have a complete desktop freeze, with the only remedy to either go to a different tty and kill the process or step away and put the kettle on while it sorts itself out.

Given that Firefox is the default browser in Ubuntu Mate, and it’s such a commonly used function, I can’t understand why it was not noticed in pre-release testing. It’s a severe bug, and a fix should have really worked its way into the repos by now. It’s not a show stopper, but its close enough in my opinion.

On the other side of the coin I can understand this is not a big commercial project like Windows. It has limited resources, and this is also not an LTS release. 17.10 is not that far away and I assume the fix will have trickled down to that release by then. So we can all upgrade then and put this one to bed.

I’m new to Mate, having been previously a long time Xubuntu user, which I only left due to the bluebird theme never being updated for GTK3. Mate is perfect, the themes are great and once you’ve got it configured, feels just like XFCE except much more modern. It’s a great desktop, long may it continue. And this bug, while really annoying is not the end of the world :slight_smile:


If you really can’t wait for the update to trickle downstream, I have just tested a procedure to deploy the caja update on my system.

Note: I don’t recommend doing the same thing if you’re worried about the purity of your system, or potential instability. It is very possible doing this is gonna break something somewhere. I have not noticed any breakage yet but that doesn’t mean there aren’t any.
Note: Tested only for amd64 and Ubuntu MATE 17.04. If you’re using a 32-bit install you need to adapt the procedure.

  • Download the binary package versions for caja 1.18.3 and dependencies:


  • Then install the dependencies and caja:

sudo dpkg -i caja-common_1.18.3-0ubuntu1_all.deb
sudo dpkg -i libcaja-extension1_1.18.3-0ubuntu1_amd64.deb
sudo dpkg -i caja_1.18.3-0ubuntu1_amd64.deb

  • Finally, reboot


The reason for that is that we don’t really have enough testers.
We’ve been discussing how to grow our testing base and test coverage but it’s not trivial.

Also, Ubuntu has a fixed release cycle so even if the bug had been spotted, it doesn’t mean the release would have been held until the bug was fixed.
There’s a very limited number of official tests done on the Ubuntu releases, and most of them concern the install process, not desktop usage.