Created Unassigned: Error while analyzing SQL 2008 R2 [24575]

Hi, i tried to analyze a SQL 2008R2 Counter, but the cmd returns the following:
Index operation failed; the array index evaluated to null.
At C:\Program Files\PAL\PAL\PAL.ps1:3424 char:69
+ $aValue = $htVariables[$XmlGeneratedDataSource.COLLECTIONVARNAME][ <<
<< $sKey]
+ CategoryInfo : InvalidOperation: (:) [], ParentContainsErrorRec
ordException
+ FullyQualifiedErrorId : NullArrayIndex

And the html generated is empty.
I am using the last version of the program and treshold files.
can you tell me why?
thanks in advance!