That might seem like the game didn't download correctly then. Can you make itch reinstall the game? That should hopefully fix the error as well. Let me know if that worked or not. If it didn't, a screenshot of the error in question would be nice.
Also, can you tell me what operating system, as well as version, you're using? The error alludes to an incompatibility with your operating system. You may want to update your OS as well.