< < ERROR >> for last values of instance discovery

[alireza.stack]

Why I get the attached error when using the below configuration: 

Parameter: FileSystem.Free([instance])
Instance discovery -> Agent list -> FileSystem.MountPoints

Why should I get an error like this? I should note that when I fetch data manually it works ok.

When I run agent on debug mode, the below result is shown: 

23-Aug-2015 14:18:41.732] [DEBUG] [session:0] Received message CMD_GET_PARAMETER
[23-Aug-2015 14:18:41.732] [DEBUG] [session:0] Requesting parameter "FileSystem.Free([instance])"
[23-Aug-2015 14:18:41.732] [DEBUG] [session:0] GetParameterValue(): result is 500 (INTERNAL_ERROR)
[23-Aug-2015 14:18:41.732] [DEBUG] [session:0] Sending message CMD_REQUEST_COMPLETED (size 32)

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[alireza.stack]

I have found the solution. As someone else might come across this thread: 

I should have used FileSystem.Free({instance}) instead of FileSystem.Free([instance]). I followed a youtube video which I think was a little bit old and it used [] rather than {}