Oh....guess I didn’t catch that “soft starter” part...oops.
At any rate, it sounds as if the VMI is looking at the Seimans “run/stop” output status and not seeing it “ready” to go. Possible Seimans Logic Card troubles on one of the two starters.
You’ve no doubt tugged and checked all wiring at each starter terminal block and at the VMI controller.
Are you scrolling back in the Fault log to see the sequence of operation prior to the CONT FAIL?
Or- Can you look at what might be the “ready” input on the VMI keypad screen while the unit is faulted to see if it’s present or not?