I somehow managed to get into a situation where all text inside of a certain document gets created with a black background. As I've understood, it's not possible to set a background color on text in the iPad app, so there is no way to remove it. I'm not sure what caused it; I saw another report about pasting in text from an external source, but I did not do that - it simply was that way on the first text I tried to create.
I managed to work around the problem by copying the contents of the document into a new document, where the issue wasn't present.
I've attached the document with this post.
Thanks for making this great app!
Untitled_1.afdesign