When QuickBooks cannot validate the digital signature of the update file, it generates QuickBooks Error 15215 during payroll updates. Usually, firewall settings, antivirus software conflicts, or problems with internet connectivity are the source of this error. It can be fixed by changing security settings or turning off the antivirus program for a while. Please call us at +1.833.802.0002 if you want to talk to a QuickBooks support specialist right now.