Could not load file or assembly 'System.Web.RegularExpressions, Version=4.0.0.0

Question

User1935984934 posted

Last night I upgraded my Visual Studio 2017 to the latest version 15.7.0. Since then **all** my projects are not running any more.
The error I am getting:

Could not load file or assembly 'System.Web.RegularExpressions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified.

I tried adding manually a referece to the DLL, I am still getting the error

UPDATE: I got the same result with a brand new project using VS 2017 v 15.7. I added a master page and a simple page, nothing more.

UPDATE 2: That same project works just fine on my spare machine running VS 2017 v 15.4 

I zipped the project and uploaded it here

Answer 1

User347430248 posted

Hi Corobori,

I try to update Visual Studio 2017 with latest update for testing your project.

I find that Latest version is 15.7.1

I try to open your project and find that everything is working as expected. I did not get any error.

Looks like, Something got corrupted in your Visual Studio.

I suggest you to repair your Visual Studio application from control panel may solve your issue.

Regards

Deepak

Answer 2

User1935984934 posted

Deepak Panchal

I suggest you to repair your Visual Studio application from control panel may solve your issue.

Actually yesterday I reinstalled VS 2017. Today, as per your suggestion I repaired Visual Studio and it did the trick Deepak. Thanks for that.