The error is due to an incorrect resources allocation; you superimposed both UE26 and UE27 on top of UE9, and that is not supported by 3GPP MUST (max. two NOMA UEs).
So, change UE27:UE9 to UE27:UE3, as it seems you forgot UE3.
By the way, the number of allocated resources is very low per user. Try to allocate at least 12 subcarriers (assuming 14 time symbols) per user if you have CQI feedback enabled, since the feedback mapping is not trained for very short block lengths. Also, for such a large number of users, set the userVelocity to 0, to speed up the simulation.
Please next time post your question in a separate topic, as this topic is only concerned with the new release details.