If QuickBooks has stopped working after update, it may be due to compatibility issues, corrupted installation files, or system conflicts. Common solutions include restarting your computer, running QuickBooks as an administrator, repairing the installation, or reverting to a previous update. You might also try renaming the QBWUSER.ini file or utilizing the QuickBooks Tool Hub to diagnose and fix issues. Ensure your system meets the software requirements and all necessary updates are installed. Contact QuickBooks support at 1.855.526.5749 for assistance with persistent issues or to speak with a certified professional.