The “VSIX” file extension would NOT open for me (when I double-clicked on it) because it was assigned to 7-Zip (for whatever reason).
I opened Visual Studio 2019 Community, and then clicked on “Extensions” and then clicked on “Manage Extensions” and then at the very bottom it said “Change your settings for Extensions” and I clicked on that. But was unable to find ANY way to install the extension.
After searching on the internet, I found this video here:https://youtube.com/watch?v=q5ZWxxd5MZk
So what I did was did a search for “Developer Command Prompt for VS 2019” and then right-clicked and “Run as Administrator”.
Then AFTER I did a search for “Developer Command Prompt for VS 2019” and then right-clicked and “Run as Administrator”.
The next step (at the command prompt) was to type:
cd \Program Files\Epic Games\UE_4.25\Engine\Extras\Unreal\VS\VS2019
Then I executed the following command:
C:\Program Files\Epic Games\UE_4.25\Engine\Extras\UnrealVS\VS2019> **vsixinstaller.exe UnrealVS.vsix **
Then the VSIX Installer window popped up (See image below)
Then I clicked on “Install” and then the “UnrealVS” (VSIX Extension) was properly installed in Visual Studio 2019 Community!
I didn’t have to make ANY of the modifications (listed by @russwb](https://forums.unrealengine.com/member/818380-russwb) in post #1) for installing UnrealVS plugin with Visual Studio 2019 (version 16.6.2) using Unreal Engine 4.25.1
I just followed the step-by-step instructions (that I created/posted above).
I hope this helps, and thank-you to @russwb](https://forums.unrealengine.com/member/818380-russwb) for creating this thread, which I was able to find using Google and doing a search on “How to install UnrealVS extension” and the very first search result took me to this thread, and I read it, and it at least got me thinking (because double clicking on UnrealVS.vsix didn’t work for me) and after findthis YouTube video here), it helped me finally figure out HOW to get the “UnrealVS” plugin installed. (Just follow my detailed instructions above, and that should get it done!)
I hope this helps!