When using B4XPages.GetPage you get the following code snippet as a suggestion on how to use this function.
The "Get" method has changed its name to "GetPage"
B4X:
Dim mp As B4XMainPage = B4XPages.Get("MainPage")
The "Get" method has changed its name to "GetPage"
B4X:
Dim mp As B4XMainPage = B4XPages.GetPage("MainPage")