6>O:Done building target "ResolveProjectReferences" in project "PL.csproj" -- FAILED.
6>O:
6>O:
6>O:
6>O:Done building project "PL.csproj" -- FAILED.
6>O:
6>O:
6>O:
6>O:Build FAILED.
6>O:
6>O:
6>O:
6>O:MSBUILD : warning MSB4056: The MSBuild engine must be called on a single-threaded-apartment. Current threading model is "MTA". Proceeding, but some tasks may not function correctly.
6>O:
6>O:C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Microsoft.Common.targets(1380,5): error MSB4018: The "MSBuild" task failed unexpectedly.
6>O:C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Microsoft.Common.targets(1380,5): error MSB4018: System.InvalidCastException: Unable to cast object of type 'System.Xml.XmlComment' to type 'System.Xml.XmlElement'.
6>O:C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Microsoft.Common.targets(1380,5): error MSB4018:    at Microsoft.Build.BuildEngine.Project.ProcessProjectChildren(XmlElement projectElement, String projectDirectoryLocation, Boolean importedProject)
6>O:C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Microsoft.Common.targets(1380,5): error MSB4018:    at Microsoft.Build.BuildEngine.Project.ProcessImportElement(XmlElement importElement, String projectDirectoryLocation, Boolean importedProject)
6>O:C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Microsoft.Common.targets(1380,5): error MSB4018:    at Microsoft.Build.BuildEngine.Project.ProcessProjectChildren(XmlElement projectElement, String projectDirectoryLocation, Boolean importedProject)
6>O:C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Microsoft.Common.targets(1380,5): error MSB4018:    at Microsoft.Build.BuildEngine.Project.ProcessMainProjectElement()
6>O:C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Microsoft.Common.targets(1380,5): error MSB4018:    at Microsoft.Build.BuildEngine.Project.InternalLoadFromXmlDocument(XmlDocument projectXml, ProjectLoadSettings projectLoadSettings)
6>O:C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Microsoft.Common.targets(1380,5): error MSB4018:    at Microsoft.Build.BuildEngine.Project.Load(String projectFileName, BuildEventContext buildEventContext, ProjectLoadSettings projectLoadSettings)
6>O:C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Microsoft.Common.targets(1380,5): error MSB4018:    at Microsoft.Build.BuildEngine.Engine.GetMatchingProject(Project existingProject, String projectFullPath, BuildPropertyGroup globalPropertiesToUse, String toolsVersion, String[] targetNames, BuildEventContext buildEventContext, Boolean toolsVersionPeekedFromProjectFile)
6>O:C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Microsoft.Common.targets(1380,5): error MSB4018:    at Microsoft.Build.BuildEngine.Engine.BuildProjectFileInternal(BuildRequest buildRequest)
6>O:C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Microsoft.Common.targets(1380,5): error MSB4018:    at Microsoft.Build.BuildEngine.Engine.EngineBuildLoop(BuildRequest terminatingBuildRequest)
6>O:C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Microsoft.Common.targets(1380,5): error MSB4018:    at Microsoft.Build.BuildEngine.TaskExecutionModule.BuildProjectFile(Int32 handleId, String[] projectFileNames, String[] targetNames, IDictionary[] globalPropertiesPerProject, IDictionary[] targetOutputsPerProject, EngineLoggingServices loggingServices, String[] toolsVersions, Boolean useResultsCache, Boolean unloadProjectsOnCompletion, BuildEventContext taskContext)
6>O:C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Microsoft.Common.targets(1380,5): error MSB4018:    at Microsoft.Build.BuildEngine.EngineProxy.BuildProjectFilesInParallel(String[] projectFileNames, String[] targetNames, IDictionary[] globalProperties, IList`1[] removeGlobalProperties, String[] toolsVersions, Boolean returnTargetOutputs)
6>O:C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Microsoft.Common.targets(1380,5): error MSB4018:    at Microsoft.Build.Tasks.MSBuild.ExecuteTargets(ITaskItem[] projects, Hashtable propertiesTable, String[] undefineProperties, ArrayList targetLists, Boolean stopOnFirstFailure, Boolean rebaseOutputs, IBuildEngine3 buildEngine, TaskLoggingHelper log, ArrayList targetOutputs, Boolean useResultsCache, Boolean unloadProjectsOnCompletion, String toolsVersion)
6>O:C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Microsoft.Common.targets(1380,5): error MSB4018:    at Microsoft.Build.Tasks.MSBuild.BuildProjectsInParallel(Hashtable propertiesTable, String[] undefinePropertiesArray, ArrayList targetLists, Boolean success, Boolean[] skipProjects)
6>O:C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Microsoft.Common.targets(1380,5): error MSB4018:    at Microsoft.Build.Tasks.MSBuild.Execute()
6>O:C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Microsoft.Common.targets(1380,5): error MSB4018:    at Microsoft.Build.BuildEngine.TaskEngine.ExecuteInstantiatedTask(EngineProxy engineProxy, ItemBucket bucket, TaskExecutionMode howToExecuteTask, ITask task, Boolean& taskResult)
6>O:
6>O:    1 Warning(s)
6>O:
6>O:    1 Error(s)