Web.config transformation: Unrecognized attribute 'xmlns:xdt'. Note that attribute names are case-sensitive

Question

I\'m getting this strange intermitent bug in a MVC 3.0 project When I build the project sometimes I get the following error message:

Unrecognized attr

Answer 1

I ran into the very same problem. You will find lots of banter out there related to MvcBuildViews and various error conditions. But none seem to mention this particular error. A quick fix that worked for me was to delete the contents of the "obj" directory for the affected web project, then rebuild.

Answer 2

1. Right click on the project, click Publish
2. Goto Settings -> File Publish Options
3. Uncheck Precompile during publishing

This will prevent the web.debug.config/web.release.config injecting the file back to the web.config if you are using visual studio publish.

Answer 3

This works with Continuous Integration and WebDeploy:

This problem occurs the moment I set

<MvcBuildViews>true</MvcBuildViews>

in my Project file, which I need to do.

After reading and testing everything I found about this problem I have a wokraround, that also works with WebDeploy via MSBuild

MSBUild.exe ... /p:DeployOnBuild=true

You (only) need to delete the TransformWebConfig subfolder in your buildfolder during the pre- AND post-build events. It even works with continuous integration servers which break if no folder exists

Pre-build event command line:

if exist "$(ProjectDir)obj\$(ConfigurationName)\transformwebconfig\" del "$(ProjectDir)obj\$(ConfigurationName)\transformwebconfig\*" /F /S /Q

Post-build event command line:

if exist "$(ProjectDir)obj\$(ConfigurationName)\transformwebconfig\" del "$(ProjectDir)obj\$(ConfigurationName)\transformwebconfig\*" /F /S /Q

This even works fine with Resharper which will sometimes get confused, if you delete the whole obj folder.

Make sure to set the Run the post-build event to always!!

UPDATE: Replaced debug and release with $(ConfigurationName) and removed resulting duplicate line

Answer 4

I just change below on web.config

<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">

to

<configuration>

It fixed the problem

Answer 5

I've also run into this issue. For me it was caused by my having created a new debug configuration called, "DevDebug". I fixed it by making a copy the web.debug.config, named web.DevDebug.config and added it to the project.

Then, when I attempted to run the aspnet compiler, it was satisfied that it could find the right configuration version of the config file to merge in.