What's the status of LED on NC450? Except playback, do other function work properly? You can check whether the FW is the latest one. If it' s not, it' s better to update firstly.

LED is solid green. The camera works perfectly, except the playback issue. Firmware and app are the latest. I can see playbacks that were captured recently ( last hour) but I cannot see earlier playbacks ( yesterday, or previous week). Thumbnails work perfectly, i cannot watch the videos. It must be a bug.