[2020] Placing Seat of Power Is crashing game.

Hello iron_brigade1,

Welcome to the forums and sorry to see your game is crashing after playing for so long.

At a glance I suspect it may be a memory issue, are you using any programs in the background that maybe be using your ram as well, causing the game to crash? These can include game overlays, VoIP programs and overclocking software, If you can disable these through task manager then launch your game, does your game still crash after placing the Seat of Power?

Here is a list of programs that can potentially cause crashes and performance issued if ran whilst Anno is launched -
https://support.ubisoft.com/en-GB/Faqs/000025721

If you can try the above then get back to me and let me know if this solved your issue or not. Then it may be worth creating a support ticket and attaching your save file for investigation.