The 'packages' element is not declared
Taken from this answer.
- Close your
packages.configfile. - Build
- Warning is gone!
This is the first time I see ignoring a problem actually makes it go away...
Edit in 2020: if you are viewing this warning, consider upgrading to PackageReference if you can
Oh ok - now I get it.You can ignore this one - the XML for this is just not correct - the packages-element is indeed not declared (there is no reference to a schema or whatever).I think this is a known minor bug that won't do a thing because only NuGet will use this.
See this similar question also.