The commercial law obligation to investigate and raise objections has long been one of the fundamental rules of commercial transactions. Despite its long history, the legal consequences of a missed objection for the buyer remain unclear in important areas. Addressing the issues surrounding the legal consequences of Section 377 of the German Commercial Code (HGB) and developing new solutions is the goal of this work. To this end, after clarifying the conditions for the application of the norm, the actual approval of a good will be examined more closely to draw conclusions about the approval fiction according to Section 377 HGB. Rights arising from breaches of ancillary obligations and torts prove to be particularly problematic. The work concludes with a comparison to the 'Draft Common Frame of Reference'.