@cdevroe I had the same, in my case it turned out to be my web host. On my new one (also on WP.com) the Android app works like a charm and uploads are no issues. Do you happen to be on Dreamhost? The only thing I have is sometimes, that the app, when I stay on the upload page, sometimes uploads twice. But then again, I use the beta-version. Shoud report this actually.
The WordPress app for Android is frustrating. Media uploads rarely work. I don’t know if I am to blame the app or my web host. This sort of thing makes it more difficult to microblog on-the-go.
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