After defeating and capturing a European colony, I am unable to move a unit from within the colony screen to a land area not already being used. For example, moving a unit to farm a tile results in an error because European will not "sell" tile.
net.sf.freecol.common.util.LogBuilder log INFO: Combat attacker=unit:47614-veteranSoldier-dragoon [Modifier model.modifier.offence (model.source.baseOffence) ADDITIVE 0.0 index=10] [Modifier model.modifier.offence (model.role.dragoon) ADDITIVE 3.0 index=30] [Modifier model.modifier.offence (model.unit.veteranSoldier) PERCENTAGE 50.0 index=40] [Modifier model.modifier.attackBonus (model.source.attackBonus) PERCENTAGE 50.0 index=50] = 6.75 defender=unit:46479-veteranSoldier [Modifier model.modifier.defence (model.source.baseDefence) ADDITIVE 1.0 index=10] [Modifier model.modifier.defence (model.unit.veteranSoldier) PERCENTAGE 50.0 index=40] [Modifier model.modifier.defence (model.settlement.colony) PERCENTAGE 50.0 index=50] = 2.25 odds=0.75 random(1.0)=0.3420097228130745 great=false Attack WIN DAMAGE_COLONY_SHIPS CAPTURE_COLONY Thu Jul 27 18:23:17 PDT 2017 Thread: 1882 net.sf.freecol.server.model.ServerPlayer clientError WARNING: Can not claim tile tile:10848: European owners will not sell. Thu Jul 27 18:23:48 PDT 2017 Thread: 1890 net.sf.freecol.server.model.ServerPlayer clientError WARNING: Can not claim tile tile:10700: European owners will not sell. Thu Jul 27 18:23:56 PDT 2017 Thread: 1894
FreeCol game version: 0.11.6 (Revision: a25076b8e) FreeCol protocol version: 0.1.6 Java vendor: Oracle Corporation Java version: 1.8.0_144 Java WM name: Java HotSpot(TM) 64-Bit Server VM Java WM vendor: Oracle Corporation Java WM version: 25.144-b01 OS name: Mac OS X OS architecture: x86_64 OS version: 10.12.5 net.sf.freecol.FreeCol main INFO: Configuration: version 0.11.6 (Revision: a25076b8e) java: 1.8.0_144 memory: 1908932608
This happened because of a neighboring european colony having claimed the space, even though no colonists were working in that particular tile.
AFAICT this is working as intended. You only defeated the first colony --- Europeans do not give up land easily! The second colony preemptively grabbed it as soon as they could. The natives do the same thing, albeit with less determination.
No further development here, closing.