Trainers are memory-specific. A trainer designed for version 1.2 will crash version 1.41. The is hard-coded to look for the specific .exe file signature of this patch.
Important: Most trainers use "memory injection" to alter the game's RAM. Antivirus software flags this as a "hack tool" (Riskware). This is a false positive. Add the trainer folder to your antivirus exclusions list before proceeding.
Launch Stronghold Crusader Extreme HD 1.41. Start a skirmish or load a campaign mission.