Hundred of errors after update to Visual Studio version 17.12.3!

Hossein Dabbaghan 26

I updated Visual Studio to version 17.12.3 and now, there is hundred of errors in Building project! My .net Core project was work correctly before updating. I checked errors but they are nonsense! All codes are correct.

Viorel 119K Reputation points

2025-01-03T10:41:39.1866667+00:00

What errors did you check?
Hossein Dabbaghan 26 Reputation points

2025-01-03T11:07:32.5366667+00:00

All error are about additional <div> tag without end (<\div>).

But I checked them. Divs are correct.

Also sometimes error with bundle minifier in building.
Hossein Dabbaghan 26 Reputation points

2025-01-03T11:46:06.07+00:00

Now, all errors gone and there is just one error:

The target "BundleMinify" does not exist in the project.
Viorel 119K Reputation points

2025-01-03T11:59:32.93+00:00

Maybe the last error will disappear too.
Hossein Dabbaghan 26 Reputation points

2025-01-03T17:44:46.2333333+00:00

No, it doesn't disappear.
Craig Burley 0 Reputation points

2025-01-09T17:19:33.1366667+00:00
I'm hitting the same problem (except the error count is well over 20,000) on a large MVC project — which had no build errors before I agreed to upgrade VS.

To remediate I've:

Upgraded the extensions I have (there are four of them, two of which needed upgrading)

Disabled all four extensions

Repeatedly shut down and restarted VS

Given the machine the night off (lol, but that sometimes actually works IME)

Rebooted the machine

Deleted (while VS was shut down) the .vs, bin, and obj directories in the project dir

None of this has had any visible effect on the issues.

Unfortunately, I'm up against a deadline of 2pm EST tomorrow (Friday 1/10) for a feature freeze and this is pretty much blocking me.

So, absent a quick fix, what's the best way to downgrade VS to what I was running earlier yesterday, which was working adequately?
Hossein Dabbaghan 26 Reputation points

2025-01-12T04:56:03.5866667+00:00

I fixed the "BundleMinify" error by installing "BundlerMinifier.Core". But now there is 170 error that they don't mean. I checked them. There is no error in code!
Anna Xiu-MSFT 30,791 Reputation points Microsoft Vendor

2025-01-14T06:31:28.7133333+00:00

Hello, could you create a new .NET Core project in version 17.12.3 and try to migrate your code into the new project? Are there any differences?
amr yakout 40 Reputation points

2025-01-16T20:01:17.2066667+00:00

i have the same issue

errors like

The type or namespace name 'MauiApp' could not be found (are you missing a using directive or an assembly reference?)

all packages give errors also like

The type or namespace name 'CommunityToolkit' could not be found (are you missing a using directive or an assembly reference?)
amr yakout 40 Reputation points

2025-01-17T17:30:53.6833333+00:00

run dotnet restore in the command prompet , solved my issue
Craig Burley 0 Reputation points

2025-01-17T19:04:52.92+00:00

Hmm, interesting! dotnet restore ....sln is part of my normal flow, and I repeatedly used it while trying to solve the issues I was having, to no avail. But it has, in the past, seemingly fixed issues that looked vaguely similar!
Hossein Dabbaghan 26 Reputation points

2025-01-18T04:51:06.4566667+00:00

@Anna Xiu-MSFT

I created a new .NET Core 9 project and migrated to it. It doesn't work and errors are left.
Hossein Dabbaghan 26 Reputation points

2025-01-18T05:00:22.7133333+00:00

@amr yakout

I ran dotnet restore. It doesn't work too. There are errors left.

4 answers

Anna Xiu-MSFT 30,791 Reputation points Microsoft Vendor

2025-01-06T03:17:23.11+00:00

Hi @Hossein Dabbaghan ,

Welcome to Microsoft Q&A!

You can close all running VS instances and try to delete the hidden .vs, bin and obj folders in the project folder.

Then, clean and rebuild your solution.

Sincerely,

Anna

If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment". Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.
Please sign in to rate this answer.
Hossein Dabbaghan 26 Reputation points

2025-01-06T03:53:59.32+00:00

I've tried it 50 times. This doesn't work. I also installed VS by VS installer. But errores are left!

Hossein Dabbaghan 26 Reputation points

2025-01-06T03:57:57.8366667+00:00

I've tried it 50 times. This doesn't work. I also installed VS by VS installer. But errores are left!

Anna Xiu-MSFT 30,791 Reputation points Microsoft Vendor

2025-01-06T09:05:01.26+00:00

Hello, could you share us a screenshot of the error message?

Did you install any third-party extensions?

You can temporarily disable or uninstall the installed extensions under Extensions > Manage Extensions > Installed.

Hossein Dabbaghan 26 Reputation points

2025-01-11T06:01:28.99+00:00

I have done before. It doesn't work.

Hossein Dabbaghan 26 Reputation points

2025-01-11T06:12:57.55+00:00

I've done that so many times. It doesn't work.

Hossein Dabbaghan 26 Reputation points

2025-01-18T05:04:11.8233333+00:00

@Anna Xiu-MSFT I disabled extensions. It doesn't work. Errors are left.
Sign in to comment

Use comments to ask for clarification, additional information, or improvements to the question.
Craig Burley 0 Reputation points

2025-01-09T20:04:50.2633333+00:00

Reverting the upgrade (back to 17.11.5 in my case) has proven to be a solid workaround.
Please sign in to rate this answer.
Deleted

This comment has been deleted due to a violation of our Code of Conduct. The comment was manually reported or identified through automated detection before action was taken. Please refer to our Code of Conduct for more information.

Deleted

This comment has been deleted due to a violation of our Code of Conduct. The comment was manually reported or identified through automated detection before action was taken. Please refer to our Code of Conduct for more information.
Sign in to comment

Use comments to ask for clarification, additional information, or improvements to the question.
Craig Burley 0 Reputation points

2025-01-16T20:38:44.7633333+00:00

Note that I also tried posting about my problem to the VS Help forum ("Tens of Thousands of Build Errors After Upgrading to 17.12.3"), but after responding to a couple of followup comments, I ran into so many issues with being able to refresh, comment further, and see the discussion at all, that I anticipate not participating further in that forum — so I'm planning to monitor and perhaps participate here.

(Problems I ran into include repeated claims that the connection to Visual Studio had been "Lost", requiring me to sign in repeatedly after having just done so, and returning error "403". As of the past hour or so, since soon after I made my recent comments/updates there, I've been entirely unable to participate in that forum due to such issues.)
Please sign in to rate this answer.

0 comments No comments
Sign in to comment

Use comments to ask for clarification, additional information, or improvements to the question.
Deleted

This answer has been deleted due to a violation of our Code of Conduct. The answer was manually reported or identified through automated detection before action was taken. Please refer to our Code of Conduct for more information.

Comments have been turned off. Learn more

Share via

Hundred of errors after update to Visual Studio version 17.12.3!

4 answers

Your answer