Huge set of KVS player enhancements:

1. Fully supports VAST 3.0 spec (except industry icons, as we never had an example of any KVS customer using it). This specifically means that KVS player now supports wrappers and advanced VAST loading techniques.
2. Fully supports VPAID 2.0 spec.
3. We changed the way how player requests VAST XML file. Previously it loaded VAST during player initialization in order to avoid any further delays when starting player. This approach worked incorrectly together with 3rd-party popunders, because in most cases player page would be displayed twice for the same user and KVS player didn't have any chance to know this fact, so that it could avoid VAST loading. The new approach will work similarly to other players, e.g. will load VAST only when clicked. We believe this will improve VAST performance for most KVS customers.
4. Mobile devices will start pre-loading main video during pre-roll advertising display. This should result in less time waiting for video to start, because in most cases video file will be buffered when user is watching pre-roll.
5. We changed controlbar behavior on touch devices when displaying pre-roll / post-roll ads. Previously controlbar was auto-hiding and displaying back on first touch on advertising, which may have resulted in less clicks and smaller CTR. We fixed that to never hide controlbar during advertising display on touch devices.
6. We fixed volume button to allow reducing volume during advertising display (mostly desktops as mobiles may not support this). Previously it only supported mute / unmute options.
7. We added support for player stats in KVS and Google Analytics. In Stats settings it will now be possible to enable stats for player events and choose where to collect them.
8. Also in Stats settings it will be possible to enable counting of playback events for every video. By default KVS counts only 'view' event, which is basically the fact of opening video player page. With this player update, it will also be possible to count a separate number of how many times a specific video was played by player.
9. IMPORTANT! All player skins are updated due to these changes. If you are using custom player skin you should also update it accordingly, because KVS will not auto-update your custom player skin.

CTR rotator functionality was enhanced in several ways:

1. First of all, we updated its old calculation method that resulted in slowing down CTR calculation. New rotator logic brings immediate CTR values that reflect the most clickable videos as they are at the given moment. Website caching will not affect CTR calculation anymore.
2. Another important enhancement is ability to configure random video inclusions when rendering videos by CTR. For example if you have already a set of videos sorted by CTR, you can allow some random videos to be displayed at several positions, so that new videos have bigger chance to get some clicks and make their way to the top. This should be configured per-list in list_videos block parameters (randomize_positions parameter added).
3. Finally we did some performance improvements in the area and came to enhancements that will reduce database load during CTR recalculation. We also added Schedule option in Rotator settings that allows increasing intervals between CTR recalculations, and also provides ability to configure 'quiet' period so that rotator is not generating any additional load when your server is under heavy traffic.

Other features:

1. Added support for WebP format in video screenshots. WebP is a modern image format promoted by Google and supported by major browsers (79.96% support coverage at this moment). The key feature of this format is HUGE - 30-50% - image size reduction in comparison with JPG while keeping visual quality almost the same. Since this format is not 100% supported, it can only be used as an addition to standard JPG format.
2. Adspyglass.com is now amoung free VAST providers list that do not require VAST subscription code from KVS! It provides integration with more than 30 popular VAST advertisers and may increase your advertising revenue without any effort from your side by automatically displaying best paid ads for every specific visitor based on their device and location.
3. Player stats were enhanced to provide more complex data than before. You can now use them to compare traffic quality from different sources (by using KVS referrer settings). If you buy or trade traffic from multiple sources, you can change stats grouping so that each row in stats indicate traffic from separate referrer. By comparing discrepancy between AVG value and actual value (shown as +-% in brackets) you can easily detect cheaters and bad traffic, as it is very unlikely that they can emulate the same behavioral pattern for player events as real traffic shows.
4. All traffic stats were enhanced to better GUI with ability to display more data columns and analytics function.
5. KVS will now support animated GIFs as video formats. It will be possible to define GIF format similarly to other video formats and require KVS to create GIF image from any uploaded video based on duration and trailer settings. For example it will be possible to create 5-seconds GIF trailers from every video.
6. In tag settings it will now be possible to configure that all new tags are created in inactive status and do not appear on site without manually activating them.
7. In Personal settings we returned back the option that allowed configuring maximum thumb size in admin panel lists. This option was previously removed with 5.0 changes.
8. In admin panel it will be possible now to configure Anonymous user as default user for any content.
9. Added display of embed code stats on start page in admin panel.
10. In billings we added support for repeating transaction postback if it resulted in error. In order to allow that we got back email and password logging into billing logs, that has been previously removed as part of 4.0.2 update
11. Import GUI was updated to show examples of expected values for each data column. Also support for Access level option was added for videos and albums.
12. In comments we changed the way how admin panel displays long comments in the list. Previously any comment longer than 200 characters would be truncated from the end. In the update we changed this to truncate the middle part, so that beginning and end of comment is always visible. Also we added additional column that can render full comment without any truncation, regardless of its length.
13. Storage server validation checks will now send referer header to avoid some special configurations that don't allow empty referers.
14. Backup plugin will use better naming convention for created backups.
15. KVS conversion engine will not support FLV output formats anymore as they are obsolete.
16. In video_edit and album_edit blocks it is now possible to specify access level field.
17. In signup and member_profile_edit blocks KVS will now fully verify the specified birth date to comply with minimum allowed age configured in setup.php (set to 18 years by default). Previously this option was used to limit the choice of available years in date selectors, but KVS never verified that the specified birth date was in the range of allowed full years.
18. If multiple active storage servers are located in the same group and KVS detects error in any of them, this server won't be used to serve content right a way.

Bugs that have been fixed:

1. [CRITICAL] NATS payment processor would result in processing error if no access packages were created for it (regression after 5.0).
2. [HIGH] Broken video files may appear when video format was recreated from itself and conversion engine was not able to fully copy it to storage server due to network error.
3. [HIGH] Model and content source functionality resulted in SQL errors under MySQL 8.
4. [MEDIUM] In some cases when background tasks were manually deleted, video source files would not be deleted.
5. [MEDIUM] Model and content source ranking would calculate incorrectly in random cases.
6. [LOW] Importing feeds incorrectly displayed the amount of deleted videos (regression after 5.0).
7. [LOW] Categories autoselection plugin did not consider tags correctly when using mixed case (e.g. Tag1 vs tag1).
8. [LOW] Bad screenshot detection logic worked incorrectly for some videos and could result in much slower screenshot creation.
9. [LOW] Player would sometimes render +1 timeline screenshot that did not exist and resulted in 404 error.
10. [LOW] FTP content uploader plugin would allow importing premium videos even if no premium formats were defined.
11. [LOW] Comments would be shifted to future dates when shifting post date of a video or album.