Alright, my friend. Finally got a second to test this. The solution is simple, and it's what I said. You were using the link from the XDA button, but that works through XDA. It's not a valid link on it's own. It works in your browser because you're logged into XDA. Open a clean browser (no temp files no cookies not logged in to xda) and paste that link, and it's going to give you the error you see in app. All you need is to get your own, direct paypal donate URL.
Solution: Create a donate button in paypal.
I just built this real quick with my own paypal link, just to show you what you'll have. I cannot make yours (or I would have done that for you), because you have to create the button's link in your own paypal account. Mine is just a demo.
So go to paypal maybe like
here.
Choose "Create your button now"
And in the code box that you get, click the tab for "email" to get just the URL, as opposed to "website" which gives you html code for a form button. See attached screenshot.
Dat's it. Use that URL, my friend.
