Seed: 5a576cd6
Biome: European Temperate
Players Skirmish Mode: 1v1
Map name: Archipelago
Sorry but under the mention that you’re age 3 There is UI showing that you have chosen your 4th landmark.
Maybe it’s more of issue of able to choose Imperial age again even you have chosen it.
P.S. Not sure but from you minimap, there seem to be 4 landmarks icon in it (unless one of them is second town center).
@Narute00100 thankyou for your reply. By the way, that account where I posted the photo wouldn’t let me log in for some reason, so I had to make another microsoft account. So this will be my username from now on.
I just logged back into the saved game and realized my 4th landmark was only partially built, so that was the issue.
Thanks for your feedback 
Cheers,
Richard