When the form is not configured through the Wizard options, the automatic validation will not be triggered. In such cases, you should validate the form manually by using the From validate() method. You could do this in the select event, in case the TabStrip is not placed in the last step. Below is an example of such manual validation:
In case the TabStrip and the nested forms are placed in the last step, you should perform the manual from validation in the done event handler. In order to ensure that the TabStrip and the nested form will be rendered by the time you are trying to get a reference to them, you may need to use setTimeout function.
I hope you will find the provided information helpful.
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