Extension could not be found. Please make sure the extension has been installed

Question

I've been working on a VS extension that creates a couple of files with some boilercode using SideWaffle and I was having a problem where, whenever I'd add a new item, my boilercode item would be under "My Custom Templates". I found this in the template-builder.props file and updated it to "Test", but when I tried again I had both "My Custom Templates" and "Test", both of which contained the same extension.

I figured VS might have cached the old name or something, so I uninstalled the extension from VS and restarted. Now the project won't build at all and gives the error:

Extension 'ProjName..00000000-0000-0000-0000-000000000000' could not be found.
Please make sure the extension has been installed.

I tried re-installing the extension using the .vsix in the Debug folder and restarting VS, but I get the same error). I could find nothing online about this and, to be honest, I'm confused as to why the project needs itself to be installed to build.

What can I do to get this project building again?

Bearden

Answer 1

After a bit of playing around I was able to figure out a solution to my problem:

I can see that an extension is added to the experimental instance of Visual Studio when you successfully build the project (I've found no other way of installing the extension (VS2013)). If you try to build the project without the extension installed on the experimental instance, the build fails.

Of course, this would mean that you could never build the project, because you need to build it to install the extension, and the extension needs to be installed for the project to build. Only on the very first build of the project is this not true. You can build without the extension installed, which will then install the extension on the experimental instance and allow future builds of the project.

If, like me, you uninstall the extension on the experimental instance, you're going to get into a catch-22 situation where the build fails, because the extension isn't installed, and you can't install the extension, because the build fails.

The solution to this was simple enough. I just had to run the project, at which point the build would fail, then choose to run the project from the last successful build. This will open the experimental instance without the extension installed, however, if you close the experimental instance, you can then build the project successfully, which will install the extension again.

I don't know exactly why this fixes the problem, but I'd love to know if anyone has any ideas.

Bearden

Hmm. I had exactly the same situation as you, except that after closing the experimental instance (which did reinstall the extension) I still couldn't build. Seems that I have to leave 'Deploy VSIX content to experimental instance for debugging' disabled (the extension is still copied and debuggable anyway thanks to the other options). – Jodeejodhpur

@oliver Nicholls Why you roll backed the edit .. it was better!! – Coz

The edit put part of my answer in a block quote, and it's not a quote. – Bearden

Same situation, Cameron's trick fixed it for me. Unchecked that option (in project properties->VSIX) ran a debug which built and ran in experimental fine. Then close out the experimental and was able to do everything like normal again. – Careen

thanks for putting me in the right directory with this answer. I really feel like the whole VSIX development is buggy and under-documented. For me, starting over completely was the only way to fix it completely. – Furst

Answer 2

This great post shows all the possible solutions: http://comealive.io/Vsix-extension-could-not-be-found/

This one worked for me: Increasing the version of the package in the .vsixmanifest file

Mayonnaise

Dam that page is gone now, only 9 months later! – Restate

This should be the solution! – Instant

Deffo best solution for me. Extension development is driving me crazy... – Diatomite

Answer 3

In my case I had to reset visual studio instance settings:

Tucky

Answer 4

This worked for me:

Disable the 'Roaming Extension Manager' extension within the Experimental Instance, which I had installed previously.

I had recently created many work-in-progress versions of an extension locally, some of which I had deleted from my local file system (as I had copies out in git land), and it's possible that I had confused Roaming Extension Manager and/or Visual Studio by doing this.

For good measure, I opened up the experimental instance, and uninstalled all of my personal extensions that I had created locally and no longer needed.

Ludivinaludlew

Answer 5

For me issue occured during developing VSIX application. By mistake I tried to debug this when the project was in Release mode. At that moment, the error above was shown.

Solution: Change the mode from Release to the Debug one.

Elayneelazaro

Answer 6

This error can be caused by using a Rebuild or Clean command against this type of project.

To recover, use whichever method works best for you from the other answers here—which may be as simple as starting a Run of the project. The resulting debug session can be stopped straight away, before the lengthy initialization of the experimental instance completes, as the required Visual Studio state has now been restored and the project has now built successfully.

Thereafter, try to avoid using Rebuild or Clean against this type of project, to prevent unnecessary recurrence of the problem.

Wolfort

Answer 7

OK, I was getting the following error when I try to build my Vs 2022 VSIX project.

Extension 'AddingSimpleCommand.193f41c8-e0ce-45be-9909-c47bbbbaad34' could not be found. Please make sure the extension has been installed. AddingSimpleCommand

So here AddingSimpleCommand is the name of the project.

I got this clue from this SO Ans

Essentially I had to clean up the Exp env.

So as described there, I Reset the Visual Studio Experimental Instance using the following command from windows cmd

C:\"Program Files"\"Microsoft Visual Studio"\2022\Professional\VSSDK\VisualStudioIntegration\Tools\Bin\CreateExpInstance.exe /Reset /VSInstance=17.0_c9ef2fd3 /RootSuffix=Exp && PAUSE

Note the quotes for Program Files and Microsoft Visual Studio. Without it you may get error as described in this SO Question

After I ran the command, this are back on track now.

Urinalysis

Answer 8

As I just had this problem as well, and most solutions did not help, i figured out a very simple one, which at least worked in my case.

• double click on source.extension.vsixmanifest
• change any metadata like Product Name, Author or Version. Probably changing product ID will help as well, but I don't know if this causes other errors.
• Rebuild

Accrescent