Just like superluig164 , my issue was resolved after a reboot. I'll post again if this changes.

In that case, the same request for a debug log (step 4b): https://www.mediamonkey.com/forum/viewtopic.php?f=30&t=86643

Single instance is checked and 5.0.1.2433

Do you have the option run only a single instance of MediaMonkey enabled under Tools > Options > General?

If so, which Build (Help > About) of MediaMonkey are you using?

I'm running into an issue where I will be using MM5 and ask windows to open an audio or video file and instead of simply playing the file through MM5, which is currently in use, Windows will open a new instance of MM where the application is now open twice. I didn't have this issue with MM4. Any ideas what it could be?

Well.

As soon as I tried to reproduce the bug, it no longer happens. I can't explain why. Perhaps it has something to do with it having been just installed, and I changed the settings around, but it didn't catch up? I dunno. Anyways, thanks for your help. Guess I don't have a problem anymore!

Sure, I'll do it when I get home from work. I can also include a screen recording if that helps.

Hi,
no, the fix is already included with the 5.0.1.2433 version

Nobody from our dev team can replicate the issue, we will need more info to see why this is happening in your environment.
Can you please open support ticket and attach debug log, Mediamonkey.ini and persistent.json , see item 4b here: https://www.mediamonkey.com/forum/viewtopic.php?f=30&t=86643 for analyzing.

Thanks!

I'm using 5.0.1.2433. The build which just got released as an update for MM4 users. I'm not running any beta builds or anything like that. If it's fixed for the next build, that's good enough for me.

So it looks that you are experiancing instance of issue https://www.ventismedia.com/mantis/view.php?id=17030 that has been already fixed in the past? Which MM5 version/build are you using?

Nope. I have mediamonkey set to close to tray. So even if the first instance is still playing music, after closing it to the tray, when I click the shortcut, a new instance opens with a different song loaded. This doesn't match the behaviour from MM4 and I am assuming it's a bug. It even shows two tray icons. It's definitely starting twice.

Hi, if you close the window then the first MM instance is closed and thus another instance is started (as the first is already closed).

But I suppose that if you keep the first instance running and click the taskbar icon to start another then another instence does not start as expected, right?

I have the "Allow only one instance" option checked, however, if I close the window and try to re-open Mediamonkey from the taskbar (I have it pinned) it will open a second instance anyways, I guess without checking to see if there was already an instance open and restoring that instead, like MMW4 did.