Ok, thanks for help.

Hey janwetzel85,
Thank you for bringing my attention to this Problem.
It could be because the Game cant connect some of the Cites and Industrys to each other because of high elevation and big bodies of water,
I use No Initial Roads [ https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=894751261 ] becuase i like to build my own highways between cites. so i never thought that. So maybe try No Initial Roads [ https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=894751261 ] , that should fix this Problem.

Map don´t working!!!!