SubscriptionLine

Hi i was wondering if others had faced this problem before.

$SubscriptionLine = array();
    $SubscriptionLine = $client-SubscriptionLine_FindBySubscription($subscription)-SubscriptionLine_FindBySubscriptionResult;
   
    return $SubscriptionLine;


I get this error result:  Economic.Api.Exceptions.ServerException(E00000): An internal error has occurred. (id=1402903862)

What im trying to do is get a subscription line based on subscriptionHandle but for some reason i can not get it to work.

Things i have tested is that A i have a subscription and i also have subscription lines.
What does this error mean. ?