title: WarningsPlugin not Collecting warnings from MSBuild
body: <p>I am experimenting with a Multibranch job. Building the solution works, but parsing the warnings generated by the build fails.</p>
  
  <p>this is my Jenkinsfile:</p>
  
  <pre><code>node {
      stage ('Checkout')
      {
          checkout scm
      }
  
      stage ('Build')
      {
          bat "\"${tool 'MSBuild VS2013'}\" Solution.sln /p:Configuration=Release /p:Platform=\"Any CPU\" /p:ProductVersion=1.0.0.${env.BUILD_NUMBER}"
      }
  
      stage ('Warnings')
      {
          step([$class: 'WarningsPublisher', canComputeNew: false, canResolveRelativePaths: false, defaultEncoding: '', excludePattern: '', healthy: '', includePattern: '', messagesPattern: '', parserConfigurations: [[parserName: 'MSBuild']], unHealthy: ''])
      }
  }
  </code></pre>
  
  <p>I get this Exception from the Warnings Plugin:</p>
  
  <pre><code>Projekt : Das Einlesen der Datei d:\jenkins20\configs\workspace\JenkinsFile_master-CQILFOMT634B5TYN4BWJKVHYYWABZMZHXNE4WK5BQE2E2MJN4MDQ ist wegen folgender Exception fehgeschlagen: java.io.FileNotFoundException: d:\jenkins20\configs\workspace\JenkinsFile_master-CQILFOMT634B5TYN4BWJKVHYYWABZMZHXNE4WK5BQE2E2MJN4MDQ (Zugriff verweigert)
   at java.io.FileInputStream.open0(Native Method)
   at java.io.FileInputStream.open(Unknown Source)
   at java.io.FileInputStream.&lt;init&gt;(Unknown Source)
   at hudson.plugins.warnings.parser.ParserRegistry.createReader(ParserRegistry.java:325)
   at hudson.plugins.warnings.parser.ParserRegistry.parse(ParserRegistry.java:281)
   at hudson.plugins.warnings.parser.ParserRegistry.parse(ParserRegistry.java:261)
   at hudson.plugins.warnings.parser.FileWarningsParser.parse(FileWarningsParser.java:44)
   at hudson.plugins.analysis.core.FilesParser.parseFile(FilesParser.java:325)
   at hudson.plugins.analysis.core.FilesParser.parseFiles(FilesParser.java:283)
   at hudson.plugins.analysis.core.FilesParser.parseSingleFile(FilesParser.java:241)
   at hudson.plugins.analysis.core.FilesParser.invoke(FilesParser.java:200)
   at hudson.plugins.analysis.core.FilesParser.invoke(FilesParser.java:31)
   at hudson.FilePath.act(FilePath.java:996)
   at hudson.FilePath.act(FilePath.java:974)
   at hudson.plugins.warnings.WarningsPublisher.parseFiles(WarningsPublisher.java:392)
   at hudson.plugins.warnings.WarningsPublisher.perform(WarningsPublisher.java:290)
   at hudson.plugins.analysis.core.HealthAwarePublisher.perform(HealthAwarePublisher.java:68)
   at hudson.plugins.analysis.core.HealthAwareRecorder.perform(HealthAwareRecorder.java:295)
   at org.jenkinsci.plugins.workflow.steps.CoreStep$Execution.run(CoreStep.java:69)
   at org.jenkinsci.plugins.workflow.steps.CoreStep$Execution.run(CoreStep.java:59)
   at org.jenkinsci.plugins.workflow.steps.AbstractSynchronousNonBlockingStepExecution$1$1.call(AbstractSynchronousNonBlockingStepExecution.java:47)
   at hudson.security.ACL.impersonate(ACL.java:221)
   at org.jenkinsci.plugins.workflow.steps.AbstractSynchronousNonBlockingStepExecution$1.run(AbstractSynchronousNonBlockingStepExecution.java:44)
   at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
   at java.util.concurrent.FutureTask.run(Unknown Source)
   at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
   at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
   at java.lang.Thread.run(Unknown Source)
  </code></pre>