问题
I have the problem that I have VS 2012 and VS 2013 installed and when I download an VSIX-File and open it with the Visual Studio version selector the file gets opened by VS but instead of installing it VS opens the file as if it was an unknown binary format.
The attached image shows how VSIX-files are opened (happens with every file ... this is just an example):

回答1:
I faced the same issue. Just use the VSIXInstaller to install the extension.
You can open "Developer Command Prompt for VS2012" tool in Start -> Microsoft Visual Studio 2012 -> Visual Studio Tools. On the console, run the below command:
VSIXInstaller <path to vsix file>
回答2:
- Open "Developer Command Prompt for VS2015" as administrator.
- Type
VSIXInstaller.exe vsixFilePath
Note that this way wouldn't work with me and gives me "Path to vsix file 'G:\Roslyn' is invaild or you don't have required access permissions". To solve this you need to put the path in a double quote like this:
VSIXInstaller.exe "G:\Roslyn SDK.vsix"
回答3:
I got into a weird situation where in a fresh install of W10 and VS2015 Community, the Player Framework vsix installation won't start, either by dbl click or from command prompt using VSIxInstaller.exe, and would show no message at all. The solution was to open an elevated command prompt (run Developer Command Prompt for VS2015 as administrator) and then type VSIXInstaller.exe worked.
回答4:
To add to the other answers, if the VSIX files either doesn't have an associated program to open with or opens with the wrong application, selecting the VSIXInstaller.exe as the associated commands re-enables the ability to double-click and directly install it (without the need to do it via commandline).
回答5:
I am not clear whether you want to install or just view the contents of VSIX. If you want to install the extension, you just need to double click it and it will install (Do not try to open it with VS Version selector). If you want to see what is inside VSIX, it is basically an archive. So either try to use program like 7-zip to open it else, rename .vsix to .zip and then unzip it.
Further, there is also a chance that you have wrongly associated vsix files to be opened with Visual Studio. In such a case it will open in Visual Studio any case.
Finally, if you have wrongly associated the vsix to open with Visual Studio, try installing the extension using VSIXInstaller.exe found in C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE\VSIXInstaller.exe
回答6:
I double clicked on this and it installed just fine.
Couldn't do it on VS2013 through the extensions dialog.
回答7:
for me the problem was the extension InstallerProjects was on network server so I had to copy it to my machine (local) and it worked
回答8:
I faced a similar issue when I first installed VS 2017
. This is what worked for me.
Resolution:
- Restart VS 2017.(I hadn't restarted it before installation)
- Install it from
Tools->Extension
&Updates.Search
for "Perforce" and install.
来源:https://stackoverflow.com/questions/25906944/visual-studio-does-not-install-vsix-files