Observation specification must be scalar if not created by bus2RLSpec. Simulink Environment for Reinforcement Learning

I'm trying to define a Simulink Environment for Reinforcement Learning describing a System. In particular, I would like to consider 3 observations (image, velocity and acceleration) and only 1 continues action as manipulated variable.

% Define observation specifications.
obsBus = Simulink.Bus();
obsBus.Elements(1) = Simulink.BusElement;
obsBus.Elements(1).Name = "image";

obsBus.Elements(1).Dimensions = [12,12,4];
obsBus.Elements(2) = Simulink.BusElement;
obsBus.Elements(2).Name = "scalarObservation1";
obsBus.Elements(3) = Simulink.BusElement;
obsBus.Elements(3).Name = "scalarObservation2";
NobsInfo = bus2RLSpec('obsBus','Model',mdl);
NobsInfo=allObsInfo;

I get this error:

Error using rl.train.marl.MultiAgentTrainer/run
Error in '
rlAreaCoverage32024/Agent A (Red)': Failed to evaluate mask initialization commands.

Error in rl.train.TrainingManager/train (line 429)
run(trainer);

Error in 
rl.train.TrainingManager/run (line 218)
train(this);

Error in 
rl.agent.AbstractAgent/train (line 83)
trainingResult = run(trainMgr,checkpoint);

Caused by:
Error using rl.env.internal.reportSimulinkSimError
Observation specification must be scalar if not created by bus2RLSpec.

The code and Simulink files are in the files attached below.

Thank you for your attention, I'll wait for your help

[Alen]

I'll wait for your help

[祥]

I have encountered the same problem, have you solved it?