Bit of a strange one...
Playing as GB in the Scramble for Africa campaign, I claimed Kimberley from the OFS, fought and won the war, and they offered me it as the peace agreement.
All was good until (after a couple of years), I got a message that I could no longer maintain the fort I had built there, as I no longer had sufficient colonial penetration. On inspection, I notice that Kimberley is now an 'unclaimed territory' and I cannot play any options there at all.
Any ideas?
I got a colony as war bounty and all the fields and the harbor dissapeared after the peace settlement. I conquered another colony but decided to leave the locals be, when I quit (and made peace) the harbor I built there dissapeared, but the depot I built stayed.