1) Is this happening also with simple scenes? (one teapot, one light, one texture used)
-?
-happens in scenes varying in complexity
2) Is this happening only with some specific scene? Is it heavy?
-happens in scenes varying in complexity
3) Can you send us all DR logs?
https://coronarenderer.freshdesk.com/support/solutions/articles/12000002065-done
4) Is the scene transferred from the master to the "working directory"?
-working directory is printed in the dr server window
5) What happens if you press the green arrow next to Max version?
-nothing
---
The "max sample intensity" error should definitely not appear in 1.7. Further questions:
6) Are you sure that you have Corona Renderer 1.7 installed on all of the machines?
7) Are you sure that you are running DR server 1.7 on all of the nodes?