Disabling Closed Captioning on Roku to Avoid Crashes on Live TV Playback

Tablo David
Tablo David
  • Updated

Since Roku's 12.5 firmware update, a subset of Roku devices have started running out of memory during playback of live TV causing the 4th generation Tablo app to crash.


Why This Is Happening

This bug manifests only on playback of broadcast TV video (MPEG-2) which is why it is not present on streaming TV apps like Netflix.

Testing at Tablo HQ revealed that when the Roku player software processes the closed captioning track on MPEG-2 video, it causes affected Roku models to run out of active memory. This leads to the eventual shutdown of the entire app. 

Processing of the closed captioning track is done by the Roku player software whether or not the viewer had closed captioning enabled during playback. 

The affected Roku models manage memory consumption differently, which is why some Roku models have not been affected. 

We have notified Roku of these findings and hope they can provide a Roku firmware update to fully resolve this so all Roku users can enjoy the benefits of closed captioning without encountering this bug.

In the meantime, we have implemented a workaround in the latest Tablo app for Roku (version # 0.8.500). 


The Workaround

Once you have updated the 4th generation Tablo app on your Roku to version # 0.8.500, a new dialog box will appear on your screen AFTER this type of memory-related crash has been detected. 

image (21).png

The dialogue will ask if you'd like to disable closed captioning to avoid crashes on your Roku. 

If you select YES, this will prevent the closed captioning track from even reaching the Roku player software which will eliminate the source of the memory-related crash.

image (22).png

Closed captioning can be re-enabled at any time by pressing the star (*) button on your Roku remote, however, this will likely result in the return of the memory-related crash until Roku can provide a fix. 


Affected Roku Device Models

The Roku models most affected by this problem are:

  • 2021 Roku Express 4K+ (model 3941X and model 3941RW2)
  • 2021 Roku Streaming Stick 4K (model 3820R2)
  • 2021 Roku Streaming Stick 4K (model 3820X)
  • 2019 Roku Express (model 3930X)
  • 2017 Roku Ultra (model 4660X)
  • 2021 Roku Ultra LT (model 4801RW, model 4802RW, and model 4802X)



How do I check to see if my Roku is running the latest version of the Tablo app?

If you already have the Tablo app installed on your Roku, and your Roku is set to automatic updates, you should see version 0.8.500 very soon. You can also check for Roku app and firmware updates manually by pressing the HOME button home on your Roku remote and then navigating to SETTINGS > SYSTEM > SYSTEM UPDATE.

What if I rely on closed captioning to enjoy TV programming via the Tablo app?

We realize the importance of closed captioning for those who are hard of hearing, have auditory processing difficulties, prefer to watch TV silently, or otherwise find captions helpful to their viewing experience. We have shared our findings with Roku and are hopeful that they can provide a Roku firmware update to fully resolve this issue so all Roku customers can enjoy closed captioning during playback of MPEG-2 video on apps including Tablo.  


When will Roku have a fix for this issue?

Unfortunately, we don't have an ETA for when Roku might release a firmware update to correct the memory allocation issues resulting from the processing of closed captioning tracks on live MPEG-2 video streams. 


If I disable closed captioning on my Roku via this new dialog box, will I still be able to use closed captioning on other apps on my Roku? 

Yes. The new dialog box disabling closed captioning on the Tablo app will only affect playback of programming within the Tablo app on Roku. It can be re-enabled at any time and you can continue to enjoy closed captioning on other apps on your Roku devices.