I suspect that part of the problem is that you’re saving the Image component’s picture value to a list that gets added to Firebase rather than the url that is generated by the green photo block. So try this: when the photo is taken, set a variable (not a list… let’s keep this simple) to the green photo block. Then see if you can save that variable’s value to Firebase in the Media property (instead of app variable list). Does that work?
I’m also curious… how long are you waiting between the time you take a photo and the time you submit the data to Firebase? Because generating the green photo block’s value can take a long time. In my experience, as much as 10 seconds or even more. This is the time it takes for Thunkable to upload the photo to Cloudinary and then for Cloudinary to return a url for that photo. It’s possible you’re not giving enough time before trying to save that value to Firebase.
If those suggestions don’t fix the problem, I recommend doing some careful debugging using a strategy I use where you insert a pair of blocks (or a function) that change a label value (e.g. “1”) and then wait a small amount of time and then repeat (e.g. “2” and so on). If you sprinkle those throughout your code, you can see the exact moment when it crashes. I provide examples of that here: Debugging in Thunkable X (Video).