Hello everyone： When I create Queue_Support Class as farther，then I create UI_Class inherit from Queue_Support Class directly, UI_class works.but when I create Update Loop class,then I click change Inheritance,choose Queue_Support as Update Loop class'farther,Update Loop class doesn't works（create error）.what's the matter? I am very sorry for that my english is very poor.

No, it means that if you change inheritance in LV2020 using the built-in G#-function, you will need to manually replace all the instances of the changed class' kernel.vi in kernel.vi with the Call by Parent node. Just search for all instances of that VI in that VI and do a replace.

Are you on LabVIEW 2020? I found a bug that happens when you change inheritance in LV2020. What happens is that all Call By Parent nodes gets replaced by the actual VI, which results in infinite recursion and out of memory error. This only occurs in LV2020.