Army of 2 Pikemen and 1 shotel cannot embark onto water, game tells me I don't have a relevant tech.

Army of 2 Shotels and 1 crossbow successfully embarked the turn before, and an army of 3 Horseman and 1 Chariot embarked 3 turns earlier.

When i try to split up the 2 Pikeman and 1 shotel the game crashes. I re-launch the game, try to embark again, take these screenshots, try to split the army again, and the game crashes a second time.

(Single player game with 4 AI, standard speed)

It may be relevant that i built the great lighthouse like 5-10 turns earlier because i wanted my embarked vessels to move faster?

(that 3 stack boat by carthage is the shotels and crossbow.)

I don't know how to upload a save or anything sorry, hopefully this is formatted well enough.

Thank you to whoever is reading this, I love the game and hope you are doing well. :)