Why can't I upload to Facebook since updating to iOS 8 (iPhone 5C)?

[iMore Question]

I have an iphone 5c, recently updated to ios 8 and now can't upload a photo to FB.

It says my password is invalid on the setting page, and I get the "enable posting from sharesheet" message. I've already checked that the settings>privacy>photos (enable FB photos) is on. It worked fine before the update.