Well I was ambushed by the Huron, and when I get to the battle my Dragoons have disappeared from the map!
Not only are the Dragoons not marching in the column with the rest of my troops, they also seem to be far, far underground:
Also, I had the advisor say that you can attach Ring Bayonets by clicking on the Ring Bayonet button (at the expense of reload time).
I don't seem to have the button for this. I did have the button for Plug Bayonets but since I researched the upgrade the bayonet button has disappeared.
I thought that perhaps it was now done automatically when you hit the melee button but my fire arcs disappear completely so I suspect that the ring bayonet button and upwards are bugged.
If anyone wants to reproduce the error I have attached the save game file:
Attachment 32745
Just send the unit in North America to directly attack the Huron town.