Ubuntu – Unity unable to bring programs to foreground

unity

Ubuntu 14.04.2 LTS, some programs are already running and shown on dash. But from time to time I am unable to switch to the program. As shown in the snapshot, SecureCRT is running and when I click its icon on the dash, all SecureCRT windows are shown but I can't switch to it. As soon as I click on the window, it disappears.

The only way to solve is to kill the process and restart it. It happens almost anything, terminal, files, firefox, filezilla etc.. It gets quite annoying when I have to kill all the processes every few hours. What's preventing me from switching to the program?

I am using 2 monitors. And I can still reproduce this issue with the second monitor unplugged.

enter image description here

Best Answer

This seems to be releated to ulimit. After increasing ulimit from 1024 (Ubuntu 14.04 default) to 65535, I have not seen this problem.

$ ulimit -n
65535

To make the change permanent, append these 2 lines to /etc/security/limits.conf then reboot

* hard nofile 65535
* soft nofile 65535
Related Question