I've been using Notepad++ Portable on a Windows server at work that I connect to via RDP. There were some issues with the server and they rebooted the machine without warning us, so Notepad++ Portable was running when the reboot occurred. Now, when I reconnect and try to run Notepad++ Portable, it get the error "Another instance of Notepad++ is already running. Please close other instances of Notepad++ before launching Notepad++ Portable."
There are no instances of Notepad++ running on the server; it's just been rebooted (and I've checked the processes tab of Task Manager to be sure). I've tried re-downloading Notepad++ Portable and running from the new download and I get the same message.
Did you try fully resetting by removing the Data directory? Note that you'll lose all your settings, of course, so you may want to back it up first.
Sometimes, the impossible can become possible, if you're awesome!
Removing the Data directory does not change the behavior. However, if I run "notepad++.exe" from the App\Notepad++ directory instead of "Notepad++Portable.exe" from the main app directory, it launches without issue. So, I appear to have a workaround at least.
If that is occurring, it is running in local mode.
I would highly suggest doing a full virus scan, a full disk scan for logical errors, and then rebooting again. Generally, this behavior only exhibits when apps are unable to set a mutex at the Windows level, which means something is screwy with the OS.
Sometimes, the impossible can become possible, if you're awesome!