Index: hbase-server/src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java =================================================================== --- hbase-server/src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java (revision 1523850) +++ hbase-server/src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java (working copy) @@ -2298,7 +2298,7 @@ // Region is not in transition. // We can unassign it only if it's not SPLIT/MERGED. state = regionStates.getRegionState(encodedName); - if (state.isMerged() || state.isSplit()) { + if (state != null && (state.isMerged() || state.isSplit())) { LOG.info("Attempting to unassign " + state + ", ignored"); return; }