Troubleshooting No Task Sequences are available (Tasksequence.xml does not exist, is empty, or is inaccessible)

 I encountered this error when working with MDT right after deleting two old task sequences. 

To troubleshoot this, I went to the logs directory in the MDT hierarchy. I specified in the customsettings.ini file to write all build logs to this specific directory:

SLShare=\\BUILD\PRODDeploymentShare$\Logs

SLShareDynamicLogging=\\BUILD\PRODDeploymentShare$\Logs\%ComputerName%

When I went into the logs, I opened up the only log there, BDD.log, and found that it could not find the task sequence specified in the TaskSequences.xml file. I then opened up the TaskSequences.xml file, which is located at %DEPLOYROOT%\Control\TaskSequences.xml. Once I opened up the XML, I searched for the task sequence no found and deleted it. That fixed the issue.