Usually, the error "Front Server Group is set to 'None'" can be seen in the Discovery log, Tune log, and Benchmark execution log. This issue is caused by not assigning any front server or front server group to some devices. Here is a way to fix this issue.
Step 1: Identify which devices do not have a front server/ front server groups assigned. If you already know the problematic device, please go to Step 2.
a.Create a new device group
b.Use Dynamic Search to find out which devices do not have a front server assigned.
Step 2: Randomly select a network device and put it on the map, or put one device on the map from the device group that you created in Step 1. Right-click on the device to enter Shared Device Settings.
Step 3: Click on the drop-down menu to select the correct Front Server/Front Server Group and Submit the changes.
If the device group that you created in Step 1 is using the same front server settings, you can apply the change to that device group.
Then run the Discovery, Tune, and Benchmark tasks again.