Bug Report: Chinese external ASS subtitles display abnormally on Emby for Apple TV

[phoesky 0]

I have this problem too; it worked fine before.

[phoesky 0]

Device Model: Apple TV 4K (2022, 7th Generation)

 

OS Version: tvOS 26.4 & 26.5

 

Emby App Version: 2.0.6

 

Issue Description

 

Chinese ASS‑format subtitles (external or embedded) have failed to display properly over the past few days. Chinese characters appear as empty boxes (see Figure 1), and video playback stutters severely. Playback works normally when no subtitles are enabled, or when English/Japanese subtitles are used.

 

 

 

 

1. The issue occurs across all videos with external or embedded Chinese ASS subtitles, not just a single file.
2. This problem has never happened in the past two years. I suspect it is related to the automatic tvOS 26.4 update. The issue persists after manually upgrading to tvOS 26.5.
3. An important observation: If I exit playback and restart repeatedly, subtitles occasionally return to normal. However, the problem reappears automatically when playing the next episode.

4.Log information: No server‑side logs are generated when streaming via the Emby app on Apple TV. I have checked thoroughly and cannot provide logs for this issue.

5.Other Apple TV media players such as Infuse play the same video files without any subtitle‑related issues.

 

[phoesky 0]

PS: All problematic subtitles so far are Simplified Chinese. I have not tried playing Traditional Chinese subtitles for the time being.

[phoesky 0]

OK, Now I found a log file

ffmpeg-transcode-5bc050a1-7683-472c-b664-bdd6166e85ba_1.txt

[phoesky 0]

Attached is the ASS subtitle file.

S02E01 - けいおん!! - BD [1080P x265 Ma10P FLAC+AACx2].chs.ass

[Luke 42537]

@phoesky

 

Hi there, let's look at an example. Please attach the information requested in how to report a media playback issue. Thanks!

 

[Luke 42537]

@phoeskyhave you tried updating to Emby Server 4.9.5?

[phoesky 0]

On 2026/5/25 at AM10点08分, Luke said:

@phoesky你试过更新到 Emby Server 4.9.5 版本吗？

I have updated the server to version 4.9.5.0, but the problem persists. The subtitles still display as hollow boxes and cause playback stuttering.

Additionally, this issue only seems to occur with ASS format subtitles that feature special colored borders (such as the subtitle file I sent you earlier). Plain black-and-white subtitles play without any issues.

When encountering problematic subtitles like these, the only temporary workaround is to close and reopen the video. After repeating this several times, the subtitles may render correctly once in a while.

I hope the feedback provided above will be of some assistance to you.