I've noticed some lingering issues regarding pathfinding (for example issuing the move command to behind an AI controlled ocean region). This will be addressed ASAP. In the meantime if this happens, please navigate around the ocean regions manually.
Also, if by any chance, you have an open battle with a coastal or island region (attacking from the sea), and the battle doesn't resolve, enter the battle view and abandon the "front". This shouldn't have been possible, but just in case ;)
Thank you for your patience and apologies for the inconvenience.
Zyggy
[FIXED] a number of situations related to attacking coastal or island regions that resulted in the attacking battalion simply saying "negative". You can now properly assault and conquer island and coastal regions from the sea (using battalions)
[UPDATED] in the second tutorial episode, moved the appearance of the supply route bottleneck marker one step earlier to make things hopefully clearer