A week ago we started using a new video codec and variable bitrate for encoding our videos. The format stays the same but some of the files may be slightly smaller (while keeping the same high quality) and most importantly it has saved us an incredible amount of time as the encoding process takes much less of our own time.
99% of customers won't notice any difference. However, some customers using old software (for example Windows 7 with the default Windows Media Player) may come across playback issues (we've had one such report so far). In such case we recommend downloading basically any good free video player that will solve the issue immediately :-) I personally recommend the PotPlayer - IMO by far the best free video player without any ads.
Thank you for understanding and we hope all of you are now enjoying our videos without any playback issues :-)