Important: Starting August 5th 2025, Appstore app submissions must be built using Kepler SDK v0.20 or newer, or the submission will be rejected.
This release has no updates to the installed SDK itself, but there are many OS level improvements and bug fixes. Key improvements include:
- Media playback: Improved video playback stability with fixes for streaming crashes, better subtitle rendering, enhanced thumbnail quality, and more accurate Continue Watching progress tracking.
- Accessibility and user interface: Improved accessibility that includes fixes to the screen magnifier, better visual feedback for launch and deeplink failures, and support for Hong Kong users with Noto Sans CJK fonts. Updated BackHandler implementation to be more consistent with Android behavior.
- System stability: Improved reliability, including better thread monitoring for background tasks, more responsive voice command handling with interruptible commands, and a more robust back button implementation.
This release requires OS 1.1 (201010441150) on your Kepler Fire TV Stick, which is compatible with the Kepler SDK v0.20. You can check your device software version by navigating to My Fire TV > About.
To validate that you have the latest version, run kepler -v and you should expect that version 0.20.3443 is returned.
OS improvements and bug fixes
- Added Hong Kong Traditional Chinese fonts (HK fonts from Noto Sans CJK).
- Added visual feedback for launch failures. It now displays a message to end users when an app fails to launch.
- Added an error dialog when clicking a deeplink fails.
- Improved the BackHandler implementation to be more consistent with Android. The JS interface now calls BackHandler.exitApp() as a fall-through if the back button has not been handled after all registered JS handlers are executed.
- Improved long voice utterances so they can now be interrupted with Alexa button presses.
- Improved screen magnifier so it automatically adjusts and aligns zoomed view with focused area, consistently displaying the area of focus.
- Fixed an issue where thumbnails would have reduced quality when using Fast Image.
- Fixed closed caption cropping issue by changing setting from CLIPPED to ALLOW when text size exceeds window size.
- Fixed an issue where the Pause/Resume ThreadMonitor would pause when moving between screens.
- Fixed an issue where some subtitles would not show all expected text.
- Fixed an issue where some media playback apps would crash after 10-20 minutes of playback.
- Fixed blank screen issue when attempting to play a channel through text or voice search.
- Fixed an issue where the Continue Watching row would not update how much of the content was played.
- Fixed an issue with Thread Monitor for headless task service so that it now remains active when an interactive component enters a background state. Previously, the background state transition for interactive components incorrectly disabled thread monitoring for both interactive and headless services due to a shared Notification Service implementation.