For you guys above and anyone else that comes here looking. I have found the solution to this problem. You need to redownload the mod installer (those python35.dll and python35_ubi.dll) that we had to put in when adding the mods at the start. https://github.com/xforce/anno1800-mod-loader click where is says 'releases' takes you to https://github.com/xforce/anno1800-mod-loader/releases then down the page a little and select 'loader.zip' Download that, and extract the files (files are dated 8/5/2020) copy files to your c:/program diles(x86/ubisoft/ubisoft game launcher/games/anno1800/bin/win64. - Assuming you installed on defaults (at least that's where my game is) It will ask you overwrite. Thats exactly what you have to do. Hope this helps everyone