CleanWPPAllFilesInSingleFolder error makes my project no longer load

Using VS2012 I created a dynamic data project. It all worked and then I started configuring the web deployment settings. I am not sure what setting I changed exactly as there was no error. However when I try and load the solution I get the following error for the project and it will no longer load.

Specified condition "$(CleanWPPAllFilesInSingleFolder)" evaluates to "" instead of a boolean. C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v11.0\Web\Microsoft.Web.Publishing.targets

I cannot see CleanWPPAllFilesInSingleFolder in the csproj file. Any ideas on how to fix this so that I can load the project once more?

I just had this issue as well. Try the following:

1. Close Visual Studio
2. Delete your .user and .suo files
3. Re-open the solution.

This worked for me.

I've found a very very weird (and working) workaround for this type of deploy issues, if you have tried closing & opening VS with no luck, try to close all open document prior to the publish process. weird huh? :)

so the complete fix-it guide for this type of issues would be like the following:

1. Try "Clean" then rebuild
2. If it's still not publishing, try closing & reopening your project again
3. Still no luck? try closing VS but this time delete all the *.user & *.suo files, then open up your solution again and give it a try.
4. Finally, if all these steps are not working, try my newest trick, close all the opened document and give it a try
5.

let me know if this has helped you :)

I closed and re-opened my solution. I'm inclined to believe it's a defect in the Preview feature as that was the only thing I did differently before it started happening. I haven't been able to reproduce it since, however.

All I did was close Visual Studio then Reopened it. Done