"An unexpected error occurred" iCloud Pages

Hey Guys, we are working on a Pages for iCloud Document.

Since yesterday no one is able to open it in browser, regardless whether from a Windows System or the latest Mac OS X/Safari/Chrome etc.

I also deleted my cache memory etc.

It says "An unexpected error occurred"

Details: null is not an object (evaluating 'this._drawableInfo.setOwningAttachment')

with a ton of more lines in the detail section...

I have a copy of the Document in my private iCloud stored and I am able to open it, and work on it with the Desktop Application.

Problem is that at least 3 people have to work on it.

So i think it has to do with the Web Application? A bug?

Thanks in advance, Max!