pcmanfm run on 100% CPU, does nothing and desktop is black

[Vaclav Petras]

Time to time, pcmanfm in Lubuntu starts eating 100% of one core (so in fact 25% of all CPUs in my case according to lxtask). I don't have any window running but if I have them, they are still open. I'm actually not sure if they are still usable (last time it happened I had none open). Desktop (controlled by pcmanfm by default as far as I know) changes color to black and resets zoom for icons. Icons are still visible and I click them and open whatever is associated, right click works as well.

In top I can see:

 PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
 20 0 837144 30096 21252 R 100.4 0.8 33:28.82 pcmanfm

You can see 33 hours but I don't think that it is a time because I don't remember that it would somehow correlate with how long I run the computer. It can be related to changing resolution or screen, I do this often.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: pcmanfm 1.2.3-1.1
ProcVersionSignature: Ubuntu 3.19.0-21.21-generic 3.19.8
Uname: Linux 3.19.0-21-generic x86_64
ApportVersion: 2.17.2-0ubuntu1.1
Architecture: amd64
Config_pcmanfm_System_Lubuntu: Error: [Errno 2] No such file or directory: '/etc/xdg/pcmanfm/Lubuntu/lubuntu.conf'
CurrentDesktop: LXDE
Date: Mon Jun 29 18:48:06 2015
InstallationDate: Installed on 2015-02-09 (140 days ago)
InstallationMedia: Lubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
SourcePackage: pcmanfm
Udisks_dump: Error: [Errno 2] No such file or directory: 'udisks'
UpgradeStatus: Upgraded to vivid on 2015-05-30 (30 days ago)

[prakhar (lveritas)]

Hi. If you're getting the same bug:

1. Log out and log back in using LXDE as the environ.
2. If you're already in LXDE, login using OpenBox.

If above doesn't work, type this: sudo apt-get install nautilus. You can install any other filemanager apart from pcmanfm.

Remove pcmanfm.
  sudo apt purge pcmanfm.
Finally, reboot.
  shutdown -r now