VM in Running (Installing Extensions) state - it seems it's failing to enable the Microsoft.Azure.Diagnostics.IaasDiagnostics plugin

My VM is in the follow state "Running (installing extensions) state. In the dashboard it appears that the IaasDiagnostics extension is not enabled. The message displayed in the dashboard is:

Enable failed for plugin (name: Microsoft.Azure.Diagnostics.IaaSDiagnostics, version 1.2.0.0) with exception 
Command C:\Packages\Plugins\Microsoft.Azure.Diagnostics.IaaSDiagnostics\1.2.0.0\DiagnosticsPluginLauncher12.exe of 
Microsoft.Azure.Diagnostics.IaaSDiagnostics has exited with Exit code: -3

How can I get this working?