Unity keeps opening new instances of Microsoft Visual Studio

Deleting the “Visual Studio Code” package in the Unity Package Manager did it for me. I had tried downloading VSCode to see if I liked it better, but then switched back by changing the “external editor” in Unity back to Visual Studio. That’s when the problem started for me. So if it helps, having the VSCode package installed in the Unity Package Manager at the same time as the VStudio package seems to confuse Unity and open up a new instance of VStudio every time you click a script in Unity. Hope that helps somebody.

My fix seems to be totally different from these, but the ideas helped. Thank you all!

Any way, here’s my path to a solution:

I used package manager for both Visual Studio Code and regular. Didn’t work but may be involved in the “fix”. Then I deleted the Library folder. Somewhere along the way I Switched Preferences/External Tools Editor to Visual Studio to none and then Reopened Unity and switched to built-in VS Editor and rebuilt solution. Fixed. In Unity 2012.2. A pain, but it worked. For anyone else who is super frustrated some of these steps may help you. No more multiple VS instances on my old mac. Happy.

Updating the Visual Studio package worked for me