Warning: An error occurred while drawing the scene: Error in json_scenetree: Could not find node in replaceChild

My matlab version is 2020(a).
It always calls the "Warning: An error occurred while drawing the scene: Error in json_scenetree: Could not find node in replaceChild" .
I had try the previous solution "opengl software" , but it didn’t work.
This is the code I complie.
Is the code have problem or matlab problem.
How can I deal with this problem?
clear all
close all
clc

ATT = 1;
DATE = datestr(now, 30);

mdl = ‘quarter_car’;
open_system(mdl)
agentblk = [mdl ‘/RL Agent’];

numObs = 5;
numAct = 2;

observationInfo = rlNumericSpec([numObs 1],’LowerLimit’,-inf*ones(numObs,1),’UpperLimit’,inf*ones(numObs,1));
observationInfo.Name = ‘observation’;

actionInfo = rlFiniteSetSpec({[0;0],[0;1]});
actionInfo.Name = ‘actor’;

env = rlSimulinkEnv(mdl,agentblk,observationInfo,actionInfo);

Ts = 0.01;
Tf = 10;

rng(0)

statePath = [
imageInputLayer([numObs 1 1],’Normalization’,’none’,’Name’,’observation’)
fullyConnectedLayer(50,’Name’,’CriticObsFC1′)
reluLayer(‘Name’,’CriticRelu1′)
fullyConnectedLayer(30,’Name’,’CriticObsFC2′)];
actionPath = [
imageInputLayer([numAct 1 1],’Normalization’,’none’,’Name’,’action’)
fullyConnectedLayer(30,’Name’,’CriticActFC1′)];
commonPath = [
additionLayer(2,’Name’,’add’)
reluLayer(‘Name’,’CriticCommonRelu’)
fullyConnectedLayer(1,’Name’,’output’)];

criticNetwork = layerGraph(statePath);
criticNetwork = addLayers(criticNetwork,actionPath);
criticNetwork = addLayers(criticNetwork,commonPath);
criticNetwork = connectLayers(criticNetwork,’CriticObsFC2′,’add/in1′);
criticNetwork = connectLayers(criticNetwork,’CriticActFC1′,’add/in2′);

criticOpts = rlRepresentationOptions(‘LearnRate’,0.001,’GradientThreshold’,1);
obsInfo = getObservationInfo(env);
actInfo = getActionInfo(env);
critic = rlQValueRepresentation(criticNetwork,obsInfo,actInfo,’Observation’,{‘observation’},’Action’,{‘action’},criticOpts);

agentOptions = rlDQNAgentOptions(…
‘SampleTime’,Ts,…
‘TargetSmoothFactor’,1e-3,…
‘ExperienceBufferLength’,1e6,…
‘UseDoubleDQN’,false,…
‘DiscountFactor’,0.5,…
‘MiniBatchSize’,64);

agentOpts.NoiseOptions.Variance = 0.5;
agentOpts.NoiseOptions.VarianceDecayRate = 1e-3;

agent = rlDQNAgent(critic,agentOptions);

maxepisodes = 2000;
maxsteps = ceil(Tf/Ts);

trainingOptions = rlTrainingOptions(…
‘MaxEpisodes’,maxepisodes,…
‘MaxStepsPerEpisode’,maxsteps,…
‘ScoreAveragingWindowLength’,5,…
‘Verbose’,false,…
‘Plots’,’training-progress’,…
‘StopTrainingCriteria’,’AverageReward’,…
‘StopTrainingValue’, 25000);

trainingStats = train(agent,env,trainingOptions);

simOptions = rlSimulationOptions(‘MaxSteps’, maxsteps);
experience = sim(env,agent,simOptions);My matlab version is 2020(a).
It always calls the "Warning: An error occurred while drawing the scene: Error in json_scenetree: Could not find node in replaceChild" .
I had try the previous solution "opengl software" , but it didn’t work.
This is the code I complie.
Is the code have problem or matlab problem.
How can I deal with this problem?
clear all
close all
clc

ATT = 1;
DATE = datestr(now, 30);

mdl = ‘quarter_car’;
open_system(mdl)
agentblk = [mdl ‘/RL Agent’];

numObs = 5;
numAct = 2;

observationInfo = rlNumericSpec([numObs 1],’LowerLimit’,-inf*ones(numObs,1),’UpperLimit’,inf*ones(numObs,1));
observationInfo.Name = ‘observation’;

actionInfo = rlFiniteSetSpec({[0;0],[0;1]});
actionInfo.Name = ‘actor’;

env = rlSimulinkEnv(mdl,agentblk,observationInfo,actionInfo);

Ts = 0.01;
Tf = 10;

rng(0)

agentOpts.NoiseOptions.Variance = 0.5;
agentOpts.NoiseOptions.VarianceDecayRate = 1e-3;

agent = rlDQNAgent(critic,agentOptions);

maxepisodes = 2000;
maxsteps = ceil(Tf/Ts);

trainingStats = train(agent,env,trainingOptions);

simOptions = rlSimulationOptions(‘MaxSteps’, maxsteps);
experience = sim(env,agent,simOptions); My matlab version is 2020(a).
It always calls the "Warning: An error occurred while drawing the scene: Error in json_scenetree: Could not find node in replaceChild" .
I had try the previous solution "opengl software" , but it didn’t work.
This is the code I complie.
Is the code have problem or matlab problem.
How can I deal with this problem?
clear all
close all
clc

ATT = 1;
DATE = datestr(now, 30);

mdl = ‘quarter_car’;
open_system(mdl)
agentblk = [mdl ‘/RL Agent’];

numObs = 5;
numAct = 2;

observationInfo = rlNumericSpec([numObs 1],’LowerLimit’,-inf*ones(numObs,1),’UpperLimit’,inf*ones(numObs,1));
observationInfo.Name = ‘observation’;

actionInfo = rlFiniteSetSpec({[0;0],[0;1]});
actionInfo.Name = ‘actor’;

env = rlSimulinkEnv(mdl,agentblk,observationInfo,actionInfo);

Ts = 0.01;
Tf = 10;

rng(0)

agentOpts.NoiseOptions.Variance = 0.5;
agentOpts.NoiseOptions.VarianceDecayRate = 1e-3;

agent = rlDQNAgent(critic,agentOptions);

maxepisodes = 2000;
maxsteps = ceil(Tf/Ts);

trainingStats = train(agent,env,trainingOptions);

simOptions = rlSimulationOptions(‘MaxSteps’, maxsteps);
experience = sim(env,agent,simOptions); matlab warning reinforcement learning MATLAB Answers — New Questions

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