how fix error train and test set are not compatible?

I have a dataset of about 7000 records. After clearing, I performed normalization and discretization operations on it.Then I applied a j48 model to it and saved it to my computer.Now I want to test this model on a dataset of 500 records. All columns in this dataset are the same as the original dataset. However, the "class" column in the test dataset has no value. But I got an error. For this reason, I also applied normalization and discretization operations to the test dataset. But I still get this error. Note that I specified the class attribute in both datasets, but again this error was displayed.

this is a screenshot of my test file:test.arff screenshot

and this is a screenshot of my train dataset file: enter image description here

and these are screenshots of errors : enter image description here

Solution

Thanks for the screenshots. The attribute "code" does not have the same values in the training and test set.

It looks like that is a case identifier, so you wouldn't expect the values to be the same. So, instead of having this as a nominal attribute, treat it as a numeric attribute.

@attribute code numeric

Let me know if this fixes the problem.