TFS Build 2015 not publishing test results

UPDATE (I have restructured this question with a new and basic solution and build as the same problem exists there)

I'm using the new build system in Tfs 2015 and I'm using Update 1. I have noticed that on the build summary screen, no test results or Code Coverage results are submitted:

I have a test step which runs and contains results and I have a .trx and a .coverage file but the test step log contains the warning:

##[warning]Failed to publish test results: The value for the Build.Id property is not within the permissible values for it.

The Build is very basic, it contains 2 steps and Code Coverage is Enabled on the test step:

Here is the build def as retrieved by the TEST REST API:

    {  
   "build":[  
      {  
         "enabled":true,
         "continueOnError":false,
         "alwaysRun":false,
         "displayName":"Build solution $/IsdDev/SQTestBuild/Main/TestBuildSystem.sln",
         "task":{  
            "id":"71a9a2d3-a98a-4caa-96ab-affca411ecda",
            "versionSpec":"*"
         },
         "inputs":{  
            "solution":"$/IsdDev/SQTestBuild/Main/TestBuildSystem.sln",
            "msbuildArgs":"",
            "platform":"$(BuildPlatform)",
            "configuration":"$(BuildConfiguration)",
            "clean":"false",
            "restoreNugetPackages":"true",
            "vsVersion":"14.0",
            "msbuildArchitecture":"x86",
            "logProjectEvents":"true"
         }
      },
      {  
         "enabled":true,
         "continueOnError":false,
         "alwaysRun":false,
         "displayName":"Test Assemblies **\\$(BuildConfiguration)\\*test*.dll;-:**\\obj\\**",
         "task":{  
            "id":"ef087383-ee5e-42c7-9a53-ab56c98420f9",
            "versionSpec":"*"
         },
         "inputs":{  
            "testAssembly":"**\\$(BuildConfiguration)\\*test*.dll;-:**\\obj\\**",
            "testFiltercriteria":"",
            "platform":"$(BuildPlatform)",
            "configuration":"$(BuildConfiguration)",
            "runSettingsFile":"",
            "overrideTestrunParameters":"",
            "codeCoverageEnabled":"true",
            "vsTestVersion":"14.0",
            "pathtoCustomTestAdapters":"",
            "otherConsoleOptions":""
         }
      }
   ],
   "options":[  
      {  
         "enabled":false,
         "definition":{  
            "id":"7c555368-ca64-4199-add6-9ebaf0b0137d"
         },
         "inputs":{  
            "multipliers":"[]",
            "parallel":"false",
            "continueOnError":"true"
         }
      }
   ],
   "variables":{  
      "BuildConfiguration":{  
         "value":"debug",
         "allowOverride":true
      },
      "BuildPlatform":{  
         "value":"any cpu",
         "allowOverride":true
      }
   },
   "retentionRules":[  
      {  
         "branches":[  
            "+refs/heads/*"
         ],
         "artifacts":[  
            "build.SourceLabel"
         ],
         "daysToKeep":10,
         "deleteBuildRecord":true,
         "deleteTestResults":true
      }
   ],
   "_links":{  
      "self":{  
         "href":"http://removed/343974ee-60a8-40ee-a103-37fa5db37c41/_apis/build/Definitions/71"
      },
      "web":{  
         "href":"http://removed/_permalink/_build/index?collectionId=808a695f-85b6-49db-a2df-ca4aaf8bbb9f&projectId=343974ee-60a8-40ee-a103-37fa5db37c41&definitionId=71"
      }
   },
   "buildNumberFormat":"$(date:yyyyMMdd)$(rev:.r)",
   "createdDate":"2015-11-19T07:43:27.977Z",
   "jobAuthorizationScope":"projectCollection",
   "jobTimeoutInMinutes":60,
   "repository":{  
      "properties":{  
         "labelSources":"0",
         "labelSourcesFormat":"$(build.buildNumber)",
         "tfvcMapping":"{\"mappings\":[{\"serverPath\":\"$/IsdDev\",\"mappingType\":\"map\",\"localPath\":\"\\\\\"},{\"serverPath\":\"$/IsdDev/Drops\",\"mappingType\":\"cloak\",\"localPath\":\"\"}]}"
      },
      "id":"$/",
      "type":"TfsVersionControl",
      "name":"IsdDev",
      "url":"http://removed/",
      "defaultBranch":"$/IsdDev",
      "rootFolder":"$/IsdDev",
      "clean":"undefined",
      "checkoutSubmodules":false
   },
   "quality":"definition",
   "authoredBy":{  
      "id":"7d24caba-6c09-4b78-8ff1-2404e0b0ec64",
      "displayName":"Rod Hall",
      "uniqueName":"ISD-NR\\Rod.Hall",
      "url":"http://removed/_apis/Identities/7d24caba-6c09-4b78-8ff1-2404e0b0ec64",
      "imageUrl":"http://removed/_api/_common/identityImage?id=7d24caba-6c09-4b78-8ff1-2404e0b0ec64"
   },
   "queue":{  
      "pool":{  
         "id":2,
         "name":"Back Office Pool"
      },
      "id":2,
      "name":"Back Office Pool"
   },
   "uri":"vstfs:///Build/Definition/71",
   "type":"build",
   "revision":1,
   "id":71,
   "name":"SQ Test",
   "url":"http://removed/343974ee-60a8-40ee-a103-37fa5db37c41/_apis/build/Definitions/71",
   "project":{  
      "id":"343974ee-60a8-40ee-a103-37fa5db37c41",
      "name":"IsdDev",
      "url":"http://removed/_apis/projects/343974ee-60a8-40ee-a103-37fa5db37c41",
      "state":"wellFormed",
      "revision":7
   }
}

What is the Build.Id that the warning refers to, how can I view it and set it?

This could even be a problem with TFS 2015 Update 1...

UPDATE I'm not sure if it matters but when I go to the Build section of the TFS Admin Console it appears to not be configured:

I have my application tier on 1 server and then I have 3 Agent Pools each with 3 Agents. There are 3 build servers each of which have 1 agent from each pool installed for a total of 9 agents. I set these up using PowerShell and I downloaded the agent from the TFS page. My builds still work Ok, it's just this tests publishing