I assume VidUp got some new users since it was verified by Google, maybe also some with heavy upload schedules. However, the app is at it’s quota limit nearly every day, after API quota limit is reached no further API interaction is possible, this means no uploading, no adding to playlists etc.
I requested more quota at Google, I am not sure how it will end, but it may take some weeks, at least it did the last time I requested more quota.