Hi @Cyber_Garret,
For problem #1, the “Cannot set headers after they are sent” error is returned when the renderData() callback is called twice in the same conditional flow.
Could you check where is it leaking by simplifying the code and execute the callback method only once and return the flow?
For problem #2, the error received during the app uninstall operation includes an error from the application code. So, could you enable debug logs in the FDK and check the logs of the issue to troubleshoot further if it’s an app issue?
Please share the relevant logs if it doesn’t seem issue from the app and I could help find the issue.