Web.config Transformation: Transform attribute is not declared

Question

I am attempting to transform my Web.config file to add rewrite rules for release builds, but I'm getting an intellisense error.

The 'http://schemas.microsoft.com/XML-Document-Transform:Transform' attribute is not declared.

Web.Release.config

It seems to compile okay without errors. But when I attempt to Publish, I do get build errors:

No element in the source document matches '/configuration/system.webServer/rewrite'
The 'http://schemas.microsoft.com/XML-Document-Transform:Transform' attribute is not declared.

The first line above is an error, while the second one is a warning. Why doesn't this work?

Note that the top of my Web.config does include the line <configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">

UPDATE:

The build error when deploying turned out to be caused by something else. So, in fact, it does build okay and I can deploy. So at this point, the question is just about why this Intellisense error/warning is appearing.

Halsey

have you tried to <add xdt:Transform="RemoveAll" /> before you do the rewrite? Else go to the XML menu choose schemas and find for DotNetConfig.xsd and choose use this schema. If this still doesn't work you could also try selecting the RazorCustomSchema.xsd and EntityFrameworkConfig_6_1_0.xsd schemas. If now it doesn't work, set in configuration the link as: xmlns="http://schemas.microsoft.com/XML-Document-Transform". Also if you use that link in the broswer you can see The resource you are looking for has been removed, had its name changed, or is temporarily unavailable. – Lorenalorene

Hi @Jonathan. I'm afraid I don't have an answer, but it seems this question has been asked before. #24059757 – Riata

You could also try adding <configSections> to the configuration and also <connectionStrings> – Lorenalorene

Appears to be a defect in Intellisense. See #24059757 – Monatomic

@Jonathan Wood: For me it cannot be published (VS2019). I am getting "namespace prefix xdt is not defined", how did you solve this? – Supervene

@Muflix: Nothing to solve. It's an issue with Intellisense. Aside from the red squigglies, it still works as intended. – Halsey

@Jonathan Wood I was able to build, but not able to publish the project via the publish wizard (the publish process stopped because of this error). But in the end I finally solved my issue with this approach https://mcmap.net/q/125256/-publish-to-iis-setting-environment-variable – Supervene

Answer 1

As suggested in How do I enable IntelliSense in VS 2013 for <rewrite> in transform .config? this is a defect in Intellisense.

• If you're using VS 2017 open "C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\Xml\Schemas\1033\DotNetConfig.xsd".

• Locate the xs:element name="rewrite" element near the end of the file and copy

  <xs:anyAttribute namespace="http://schemas.microsoft.com/XML-Document-Transform" processContents="strict"/>
  

  to the end of the rewrite element.

As soon as I saved the file Visual Studio removed the warning squiggly.

Someone should probably raise this with the Visual Studio team.

Monatomic

I've raised the issue through Visual Studio Feedback. developercommunity.visualstudio.com/content/problem/67412/… – Monatomic

This still appears to happen in VS 2019, but the fix doesn't fix it. – Pliers

@Neo: Were you able to get around the above problem? – Trojan

@Trojan Not that I recall, but it's been a while since I worked with Web.config files now. – Pliers

Appears also in VS 2022 – Tours

Suggested fix did not work in VS2022 v17.8.3 – Daystar