The thefts, apparently part of a coordinated and well-organized effort, happened in February but were only reported on Sunday by Spiegel.
The software bug caused the video-roulette machines to dispense money when the combination of numbers 1936 was pushed just before pulling down on the lever, Spiegel reported.
Some businesses were cleaned out of as much as €100,000 over the course of the night.
But the real loser may be Paul Gauselmann, whose company produced the machines. The company had distributed some 100,000 machines all over Germany and may be liable for the costs incurred by its clients.
The combination was likely published on the internet in exchange for money, according to Mario Hofmeister, a representative of the company contacted by T-Online.
But Hofmeister denied that Gauselmann's company would be liable given that the machines were not used in an authorized manner.