QWRK Inc.'s software product has just released an update for their application. Soon, the hotline is overwhelmed with calls about a defect. What is the MOST LIKELY thing to have occurred?

Domain 6: Security Assessment and Testing Practice Questions
Questions from the following topics are included in this domain: 
Designing and validating assessments and tests
Conducting security control testing
Collecting security process data
Analyzing test output data and generating reports 
Conducting and facilitating security audits