Parallels Desktop 17 is quite old and may not be fully compatible with macOS Monterey 12.6.7 installed via OpenCore Legacy Patcher on an iMac 2011.
Try the following steps:
Reinstall Parallels Desktop 17 using the latest build from your account.
Grant Full Disk Access to Parallels in System Settings.
Disable any third-party antivirus software.
Reinstall OpenCore Legacy Patcher root patches.
Check the crash logs in Console for specific error messages.
If the issue persists, consider upgrading to a newer version of Parallels or using an alternative like UTM or VirtualBox, which may work better on unsupported Macs.