I'm quite desperate with this. I played until the mission, where I'm supposed to move ti another base. I took the tree house base and my old church base got abandonded with all the upgrades, which already pissed me off... Now I want to retake the church outpost, but it doesn't let me. I have literally tried everything. I have enough people, enough materials and enough points. I cleared out the area and made sure to go in every room. I restarted the game several times - nothing. It just won't let me claim any more outposts. Any other solution?