During interactive stacking, I get this error:
You selected 8 unit(s): #1: ID=2, #2: ID=3, #3: ID=4, #4: ID=5, #5: ID=6, #6: ID=7, #7: ID=8, #8: ID=9,
T=2h5m50.7: Error! stack interactive-setup option 2: link 9/2/1 to 1/2/4 has different offset.
On ports 9/2/1, 9/2/2 and 1/2/3, 1/2/4 there are fiber cables connected between them, rest of the cables between switches are DAC cable.
What is this? what is offset?
I am not sure about the error reported on the offset, however, I can notice that there are 8 units selected while you attempt to number a 9th unit. Might it be related?
Would you try by numbering the units from 1 to 8?
That would be a good testing just to confirm whether it's related or not.
Let me know if you got to accomplish it.