Most of the time, the problem will come from cache replication layer, i.e., JGroups package. On the output window, you can see the JGroups membership view. See if it is updated when you run the BSH commands. It should show a view with at least two members. For example, on my window, I see

[java] ** view change: [BWANG-HOME:4381|1] [BWANG-HOME:4381, BWANG-HOME:4383]
            

with 2 members: 4381 and 4383. On the other hand, if you don't close the previous running cache instance, the membership view will also include the previous existing ones. This can corrupt the states. So you will have to make sure there is no running TreeCache processes before each demo. If you have problem with this, please consult the JGroups website