Make sure You have library assets installed/shared in all computers.
If You do have any problems here is my troubleshoot steps:
First thing to try is to make a scene of plane and teapot and scatter teapot on that plane. Create slow bruteforce rendering settings so all computers can join in rendering on time.
This way You will find out if ForestPack is working across Your network. If it renders teapots with all nodes then Your assets are not installed/shared correctly.Many tips can be found in this topic
with few links going further which are useful to troubleshoot distributed rendering issues.
Hope this helps. If You need help after reading mentioned posts please share what You did and what (is)/(is not) working for You.