Game Freezes When Loading Transport Divisions

[Sir Dave 05]

I have been playing a UK 1920 campaign for a couple of weeks now with no issues.  A battle has come up where I am defending a convoy from 3 destroyers, however when I attempt to start the battle the loading screen appears with the divisions being created in the bottom right and when it gets to a transport division the game freezes.  I have waited for over an hour and whilst the music still plays it is still stuck on loading the same transport division.  I have restarted the game a number of times but the same issue occurs when I try to load the battle.