If you are using an unlicensed copy of WinOLS, you will likely never fix this error permanently. Every Windows update, every antivirus definition update, and every reboot has the potential to re-trigger the issue. The only permanent solution for unlicensed users is to purchase a legitimate license from EVC.
For genuine users, WinOLS checks your system date against your license's "Update Period." If your system date is set to a time when your license wasn't valid, it triggers a red flag. winols your system date is wrong