So my setup is one faulty URL and a working URL. The faulty URL is supposed to fail and then call the second URL. So like a backup.

In the editor, that leads to the following error after loading the faulty URL and going for the backup:

"ToString can only be called from the main thread."

In the game, it seems to work a few times, but on the third reload of a faulty URL, it leads to some kind of varient of:

"Cannot retrieve heap variable of type 'UInt32' as type 'Single'".

Each time for a different part of the code.