"Path has been blocked"

[UNiMEDiA]

I have a paladin in the water, riding a group of serpents and kraken. There is also a medusa on the stack.

I attempted to kill a group of enemy units in the water, it would not let me attack, giving me the message in the subject line.

I ungrouped the medusa and paladin and it let my sea units kill the units in the water. I regrouped my units after the battle but now i cannot move my paladin at all without the message.

[SnotlinG]

What is the gamename? I need to test with your group