Post-processing failed in Random Builds

Implemented SonarQube with VSTS Build and during Run Code Analysis Task getting below mentioned error:
Note: This error is coming randomly, sometime Build is green and sometime we get the below error, please suggest!
MS Build version is: 14.0 and 15.0

ERROR:
The SonarQube MSBuild integration failed: SonarQube was unable to collect the required information about your projects.
Possible causes:

  1. The project has not been built - the project must be built in between the begin and end steps
  2. An unsupported version of MSBuild has been used to build the project. Currently MSBuild 14.0 and 15.0 are supported
  3. The begin, build and end steps have not all been launched from the same folder
  4. None of the analyzed projects have a valid ProjectGuid and you have not used a solution (.sln)
    14:01:50.007 Post-processing failed. Exit code: 1
    H:\Agent12_tasks\SonarQubePrepare_15b84ca1-b62f-4a2a-a403-89b77a063157\4.6.0\classic-sonar-scanner-msbuild\SonarScanner.MSBuild.exe failed with return code: 1