And it is from the GOP. And it is in the city of Philadelphia.
The Republican complaint is that there were votes already cast on the machine before they were put in service today.
The Democrats claim that they are merely the number of votes that the machine has had done on it ever. Meaning if the machine was used in a primary, and had 500 votes cast, it has some sort of counter on it (like a car odometer) that will say it has been used for 500 votes in its lifetime. It does not mean that it has 500 votes in it that will be applied to this election before anybody votes on it today.
Anyway, this is either Republican voter suppression (Philadelphia goes strongly Democrat), Democrats trying to fabricate votes, or simply somebody misinterpretting the situation and suing to be safe.