Question: Recently the issue has occurred where launching Foxit Reader does not open an active window on the desktop. Launching it from its `.desktop` file shows the icon appearing on the Unity bar with an orange dot (I assume indicating the application is running), but clicking on it does not bring up it's window. The Foxit Reader tab also appears on the top panel. Right-clicking the icon in the Unity bar and selecting All Windows does indeed show what I should be seeing on the desktop, but even selecting that does not bring it up.
I don't know if there is any way too fix this or perhaps install it's `.run` file as root? Tried uninstalling it and rebooting followed by a reinstall but nothing seems to work.

Answer: 
Verify if the process is running: `ps -ef | grep foxitreader`

Kill the process

Try to open foxitreader again
Since I open the FoxitReader via GUI, I used the top command to check a running FoxitReader process. This worked with me:

```
$ top | grep Foxit
$ kill <process-id>

```