What constraints are placed on Ideal Air Loads that would cause it to be unable to meet setpoint?

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As a follow-up. There is indeed a constraint placed on Ideal Air Loads (alluded to in the following error):

  ** Severe  ** InitPurchasedAir: For ZoneHVAC:IdealLoadsAirSystem = UNDERGROUND IDEAL LOADS AIR SYSTEM serving Zone UNDERGROUND
   **   ~~~   ** ..the minimum supply air temperature for cooling [13.00] is greater than the zone cooling mean air temperature (MAT) setpoint [10.00].
   **   ~~~   ** ..For operative and comfort thermostat controls, the MAT setpoint is computed.
   **   ~~~   ** ..This error may indicate that the mean radiant temperature or another comfort factor is too warm.
   **   ~~~   ** Unit availability is nominally ON and Cooling availability is nominally ON.
   **   ~~~   ** Limit Cooling Capacity Type=NoLimit

There does not seem to be a way to change this constraint on minimum supply air in the OS interface; however, I reduced it to 1C in the idf and it seemed to solve the issue.