Why is my Custom-UI App showing a blank page

Hello community,
when starting to develop a custom-ui app, it was showing a blank page only. After some days I figured out that I needed to move api calls from frontend to backend to make them work. The app displayed as expected. I assumed that some security mechanism sneaked in an disabled the whole app output.

Now, I added some code and suddenly the blank page is back again. :frowning:

Is there a debugging mechanism to find out the reason for the blank page?

Hi, yes there are several debugging mechanisms. you can use console.log() in your code and then open the developer console in your browser (usually with F12), switch to the console tab and look for the console.log() output. Any errors thrown should also show up there. You can also use the forge tunnel and watch the backend output.