"the outputpath property is not set for this project" error

Usually this happens when the OutputPath property of the project file is blank. Project files are just MSBuild files. To edit in Visual Studio: Right click on the project, pick "Unload project" then right click on the unloaded project and select "Edit ...".

Look for the Release-Versionincrement property group. It should look something like

<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release-VersionIncrement|AnyCPU' ">
  <OutputPath>bin\Release-VersionIncrement\</OutputPath>
  <DefineConstants>TRACE</DefineConstants>
  <Optimize>true</Optimize>
  <DebugType>pdbonly</DebugType>
  <PlatformTarget>AnyCPU</PlatformTarget>
  <CodeAnalysisUseTypeNameInSuppression>true</CodeAnalysisUseTypeNameInSuppression>
  <CodeAnalysisModuleSuppressionsFile>GlobalSuppressions.cs</CodeAnalysisModuleSuppressionsFile>
  <ErrorReport>prompt</ErrorReport>
</PropertyGroup>

The important one there it the OutputPath, does it exist for your project file? If not add it and try again.

I had the same problem when I used MSBuild first. My solution is: use the OutputPath property definitely. Like this:

msbuild XXX.csproj /p:OutputPath=bin\Debug.

In our case we were running a build script on our HP developer boxes. HP have some environment variables they've set up for their own purposes and one of them is PLATFORM (used, apparently, for "HP Easy Setup").

Deleting the PLATFORM environment variable worked.

You could also future-proof your build script by specifying the platform, i.e.
msbuild /p:Platform=AnyCPU.

The issue had to do with my project configuration. Here is the scenario:

Solution A references:

Project X references Project Y
Project Y

Solution B (the one I am trying to build) references:

Project X Project Z

My solution was to create a configuration with the same name for Solution A, rebuild it, and then rebuild Solution B. This fixed the problem.

When I added new solution configuration in my solution, I got an error, "The OutputPath property is not set for project X. Please check to make sure that you have specified a valid combination of Configuration and Platform for this project. Configuration='QA' Platform='AnyCPU'. This error may also appear if some other project is trying to follow a project-to-project reference to this project, this project has been unloaded or is not included in the solution, and the referencing project does not build using the same or an equivalent Configuration or Platform. ProjectY".

In my case issue was due to highlighted part of the error description. Project X part of my solution was having a project reference to ProjectY of another solution(different branch).

I've resolved this issue by modifying project X to use project reference to ProjectY in the current solution. Hope this helps someone having similar issue.

Just had this with VS2015 Professional:

The OutputPath property is not set for project 'xxxxx.csproj'. Please check to make sure that you have specified a valid combination of Configuration and Platform for this project.

This is also multi-project juggling between debug/release and different targets. I had been fiddling with build configurations at some point and I know that can mess up VS, so I pulled them back from the repo. Still no good. OutputPath was set, there were no longer any diffs with a known good state so there was definitely something wrong with my local installation.

Opened up VS2015 installer and clicked "Repair", and voila... back to normal (so far at least!)

For me it was a line in the NuGet package configuration. Get rid of everything package related in your project file and see come back to life (save the edits). Than build it up again part by part. I brought it down to this line which I had to remove:

<Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />

I got the problem after an update of NuGet packages (mainly FxCop analyzer stuff).

For me it was my .csproj file having multiple groups

<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">

where

<OutputPath></OutputPath>

was empty.

Filled with bin\debug and the error went away.