One more exception for a chm file:
System.IndexOutOfRangeException: Index was outside the bounds of the array.
at .(Int32 , Byte[] )
at .(Int32 )
at .()
at e.( )
at .e ()
at e.ReadLine()
at e.ReadLine()
at .()
at .(Cancellation )
at .( )
at .(Document , , String )
System.IndexOutOfRangeException: Index was outside the bounds of the array.
at .(Int32 , Byte[] )
at .(Int32 )
at .()
at e.( )
at .e ()
at e.ReadLine()
at e.ReadLine()
at .()
at .(Cancellation )
at .(Document , , String )