All of the severe errors are related to the fan operating mode schedule assigned to fans of the VRF terminal units. I'll just paste the portions of the first one below and explain what information they convey:
** Severe ** ZoneHVAC:TerminalUnit:VariableRefrigerantFlow = ETAGE5:BUREAUXNORD VRF INDOOR UNIT
** ~~~~ ** For fan type = Fan:ConstantVolume
** ~~~~ ** Fan operating mode must be continuous (fan operating mode schedule values > 0).
Your model has a VRF terminal unit named ETAGE5:BUREAUXNORD VRF INDOOR UNIT that contains a constant volume fan. That constant volume fan has an input field for fan operating mode schedule that requires a schedule with values > 0 to run as a continuous fan.
** ~~~~ ** Error found in Supply Air Fan Operating Mode Schedule Name = 8:00 - 18:00 7/7
** ~~~~ ** ...schedule values must be (>0., <=1.)
The name of the input field I mentioned above is Supply Air Fan Operating Mode Schedule, and the name of the schedule assigned to this input field is 8:00 - 18:00 7/7.
In the DesignBuilder user guide section for the VRF Indoor Unit, it mentions that if you do set Fan Type to 2-Constant volume fan then the Supply Air Fan Operating Mode Schedule values are never 0 and the fan operates continuously. My best guess without seeing your model is that the 8:00 - 18:00 7/7 schedule has values of 0. You should change this so that each VRF terminal unit has an "Always On" schedule or something similar where all schedule values are >0 assigned to the Supply Air Fan Operating Mode Schedule input field.