How can I fix "another instance of SomeApp is currently closing.." error message?

Question

I just tried to open PuTTY Portable and got the following error:

I have checked Task Manager and can't see that PuTTY Portable is running, despite what the message says. What could be going on?

Solution

Go to the directory of where you installed your program. Then go to Data, there should be a file called PortableApps.comLauncherRuntimeData-FeedNotifierPortable.ini (with the name of your respective program after the dash). The Status was probably stopped or running (meaning the program was probably closed abnormally), change it to stopped, save & exit. Copy the path in the PluginsDir, then go to that path & you'll see another file runtimedata.ini, open it. Change the Status to stopped as well. Now open task manager & kill your respective application or do a reboot (to ensure its not running). Then try to launch normally :)