Reaching out to others! Free & Open Source Software, Kannada, L10n, L18n Data Science, Cloud Computing & more…

Fix for “track format is unknown” – YouTube Error

Blogs, General, QuickFix, Technical | 0 comments

I was desperately trying to add captions to one of my video and couldn’t really get it right on youtube for some reason.

When ever I tried upload a subtitles file (.srt or .sub) which found to be working on my system, youtube used to bailout with following error:

File upload warning
The caption has been saved, but there were following errors in the file
track format is unknown

I did follow Youtube help page available at:

But I missed to look at FS (Fractional seconds) format that I had used in my .srt file.

For example:

Look at the time code example:


Timecode: Specifies when the caption should be shown, and for how long.

Time is measured from the start of the video in these units:

* HH – Hours starting at 00
* MM – Minutes (00-59)
* SS – Seconds (00-59)
* FS – Fractional Seconds (0-999)

This is where exactly I was making a mistake. instead of a period (.) I was using comma (,). As per the help page HH:MM:SS,FS –> HH:MM:SS,FS should work without any issues.

The same .srt file which without any changes works on all players that I have got on my laptop. I was forced to change all comma’s to periods and also don’t forget to remove any extra spaces in Time code before you upload the .srt file to Youtube.

Now all is good so far. But still facing issues related to Unicode (utf-8) subtitles. I shall write to Youtube once again or embed the subtitle before posting it.

Related Articles


Imagining the universe

Imagining the universe

I happened to spend this morning working on this art work with my 4 year old daughter. She did the background as she always likes to pour the colors on canvas and see that it has shades. She enjoys watching them and see that that itself blends into an abstract. Our...

read more