What is QuickBooks Error 15215?

This error transpires while we try to download a payroll update and pops out on the screen, saying QuickBooks
faces difficulty verifying the file's digital signatures.
When more than one application runs in the background, it restricts QuickBooks payroll from connecting to the server.
The different circumstances under which this error takes place are:
When other background applications will restrict QuickBooks from making internet connections. QuickBooks payroll got affected due to viruses and malware.
You have downloaded the defective file of QuickBooks software.
When QuickBooks is facing trouble in verifying the signature of the file.
In addition, a pop-up comes on the screen with QuickBooks error code 15215, stating that it cannot verify the digital signature. When your operating system starts crashing and stops working.
The system works slowly, and after some time, it freezes.