Description: After transitioned into an Early Modern culture, or loading an Early Modern culture save, the visuals of all the Harbors will disappeared from the map. The Harbors are still there, providing yields, it is just you cannot see it entirely.

Steps to reproduce:

Route A: Build Harbors in the Medieval Era; transition to an Early Modern culture; wait for the new era animation to finish; continue in the game, the visuals of all the Harbors will sometimes vanish.

Route B: Load a save of an Early Modern Era game with Harbors; sometimes the Harbor visuals will vanish in this situation as well.

Reproducibility: 2/5 or 3/5. Sometimes the visuals are still there after transitioned into Early Modern, but after several turns of playing it can disappear again.

Notes:

1. If building a new Harbor after the visuals of all the Harbors have vanished, the new Harbor will have normal visuals; keep playing, after a turn or two, all the Harbors will suddenly become visible again.

2. Saving and loading a game will not make Harbor visuals reappear.

Screenshot:

In the below picture, as one can tell from the Harbor icons and the yields, I had covered the coast of this region entirely with Harbors. However, none of the Harbors can actually be seen, as if the coastlines are still undeveloped.