Why do I get a DataQueue error?

When running my matlab app from app designer I get this error message directly in the fist line (classdef) (GUI_V3):

Error using parallel.internal.dataqueue.AbstractDataQueue/construct
Failed to load the DataQueue. A DataQueue can only be loaded in a MATLAB client or one of its pool workers if any of these created
it.

Error in parallel.internal.dataqueue.AbstractDataQueue (line 88)
                obj.construct(arg);

Error in parallel.pool.DataQueue (line 48)
            [e-mail](varargin{:})

Error in parallel.internal.dataqueue.AbstractDataQueue.loadobj (line 172)
                obj = constructorFcn(S);  

console returns this:

Warning: While loading an object of class 'parallel.pool.DataQueue':
Failed to load the DataQueue. A DataQueue can only be loaded in a MATLAB client or one of its pool workers if any of these created
it. 

I didnt get this error earlier. It just suddenly started appearing a while ago when reopening the app. The only application i used was app desginer and classification learner. I am not sure but I believe the issue is in line 62 (GUI_V3) when loading the trainedModel as I dont directly get the error when training a new model and loading it, but it eventually starts appearing for the new model too.

I tried loading it like this:

oClassifier = load('trainedModelV7.mat');

This is the used dataset: https://www.kaggle.com/datasets/aryashah2k/breast-ultrasound-images-dataset

The project I'm working on is due tuesday so I'd be glad for anyone helping me.

Thanks in advance

Answer 1

[Rasmita]

Hi,

It is my understanding that, while running the MATLAB app in appdesigner, you are getting above error message. It suggests that there is an issue with loading the ‘parallel.pool.DataQueue’ object, and that it can only be loaded in a MATLAB client or one of its pool workers if it was created by any of them.

However, from the information you provided, it seems that the issue is related to loading the ‘trainedModelV7.mat’ file, and not with the ‘DataQueue’ object. As the error appears when loading the trained model, it is likely that there is a problem with the saved file itself.

Here are some things you can try to troubleshoot and resolve the issue: 1. Check that the trainedModelV7.mat file is saved correctly and can be loaded by another script without issues. Try to load the file in a new script to make sure it is valid.

2. Check that the trainedModelV7.mat file is in the right format and contains the necessary data for your app. Maybe try to save the model again or inspect the file contents in MATLAB to ensure that it contains the expected data.

3. Make sure the path to the trainedModelV7.mat file is correct.

4. Consider using a different method to load the trainedModelV7.mat file. For example, you could try loading the file like this instead:

oClassifier = matfile('trainedModelV7.mat'); 

For more information on ‘matfile()’ function, refer this:

https://www.mathworks.com/help/matlab/ref/matlab.io.matfile.html

If none of these solutions work, you could try clearing the MATLAB workspace and restarting MATLAB to see if that resolves the issue.

Hope this helps!

Regards,

Rasmita