Only one machine of many renders wrong?
I don't really see where is the problem in the attached image? Lighting is wrong above red line ? Or is it missing textures?
Maybe that machine does not see the texture location ?
Do You have library assets installed/shared in all computers?
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 still need help after reading mentioned posts please share what You did and what (is)/(is not) working for You.