This is a summary of the cluster:

2-8 Workers

32-128 GB Memory

8-32 Cores

1 Driver

16 GB Memory, 4 Cores

Runtime

10.5.x-gpu-ml-scala2.12 

(3) what is the value set for tuner_max_evals? Right now it's been set to 36, but with every value of this, we receive the error.