Protected application is tracking system date and time on each run.
In case system time is turned back and it's outside of "Allowed system time adjustment limit" (if this option is enabled in general setting) application will consider system time as invalid.
Two things could happen at this point:
1. If "Reset license in case of invalid system time" (remote protection settings - limited license) enabled, application will reset license in case of invalid system time, display error message and ask for new activation code.
2. In case "Reset license in case of invalid system time" option is disabled, application will just display warning message (Demo_SystemTime_Error: 'System date/time error! Please correct your system date/time') about invalid system time and quit.
User should correct system time by setting it to correct system time (ahead of last recorded system time) in order to be able to enter protected application again.
If this is for some reason not possible, new update protected with "Reset license in case of invalid system time" option enabled will reset license due to invalid system time and ask for new activation code.