this.Page is not a function

This error message usually occurs when the Page object is not properly defined or initialized in your JavaScript code.

To resolve this issue, you can try the following steps:
1. Make sure that you have included the necessary JavaScript libraries and dependencies in your code.
2. Check that the Page object is defined and initialized before calling the function.
3. Verify that the function you are trying to call is a valid function of the Page object.

If none of the above steps work, please provide more information about your code and the specific error message you are seeing, so that we can further assist you.