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Custom font upload not working #72265
Description
Description
When trying to install this font it wouldn't complete and instead we are seeing a browser console error.
Step-by-step reproduction instructions
- Go to Appearance > Editor
- Styles > Fonts
- Try uploading this font:
AaDaoShuRi-LangManHeiTi-2.ttf.zip
Screenshots, screen recording, code snippet
The console renders:
Uncaught (in promise) SyntaxError: Invalid font data in ArrayBuffer
Th workaround is to convert it to a .woff2. I've used https://transfonter.org/
Environment info
WordPress 6.9 and the current stable version
Please confirm that you have searched existing issues in the repo.
- Yes
Please confirm that you have tested with all plugins deactivated except Gutenberg.
- Yes
Please confirm which theme type you used for testing.
- Block
- Classic
- Hybrid (e.g. classic with theme.json)
- Not sure
Activity
[-]Custom font upload not working:[/-][+]Custom font upload not working[/+]sidharthpandita1 commentedon Oct 11, 2025
https://github.com/user-attachments/assets/868fde54-ace1-4412-80dc-05df866644fc
i was able to upload!
Robertght commentedon Oct 12, 2025
👋 @sidharthpandita1 I'm still able to replicate this with WordPress 6.9 and Gutenberg 21.8.0 using Studio. I wonder if there's an environment situation here. Could you share what environment you are using?
t-hamano commentedon Oct 13, 2025
@Robertght If you're using Studio, your WordPress environment runs directly on the host OS, so the OS may be relevant to your issue. It would be helpful for the testers if you could tell us whether you're using Windows or Mac.
Robertght commentedon Oct 13, 2025
I'm using macOS Tahoe here
t-hamano commentedon Oct 14, 2025
The zip file attached to this issue contains a woff2 file. Is it this woff2 file that is causing the problem? Or is the problem with the font before converting it to woff2?
Robertght commentedon Oct 14, 2025
@t-hamano Sorry about that! I uploaded the ttf now. The .woff2 is the one that works.
sidharthpandita1 commentedon Oct 20, 2025
yes, facing same issue
github-actions commentedon Nov 20, 2025
Hi,
This issue has gone 30 days without any activity. This means it is time for a check-in to make sure it is still relevant. If you are still experiencing this issue with the latest versions, you can help the project by responding to confirm the problem and by providing any updated reproduction steps.
Thanks for helping out.
FakhriAz commentedon Nov 20, 2025
Reproduction Report
Description
Uploaded the .tff file and no upload was possible in the typography > fonts.
Converted the .tff file to .woff2 as using the site you provided above: https://transfonter.org/, the font was uploaded successfully.
Actual Results
✅ 2. Solved when using a .woff2
❌ 1. Error condition occurs with .tff
Environment
Supplemental Artifacts
❌ Video of the test uploading the .ttf file.
Screenshot of the console log after performing the .ttf file upload
✅ Video of the test uploading the .woff2 file.
Mustafabharmal commentedon Mar 6, 2026
I’m not able to reproduce this on the current
trunkbranch. Is the issue still present, or has it been resolved since the original report?TTF.Fond.Upload.mov
t-hamano commentedon Mar 7, 2026
@Mustafabharmal What font file did you test with? In my case the problem is still not resolved.
Mustafabharmal commentedon Mar 7, 2026
@t-hamano I have tested it with the .ttf file mentioned here.
Mustafabharmal commentedon Mar 8, 2026
I've been investigating this and can confirm the root cause. The issue is not reproducible in Safari but it consistently fails in Chrome.
The error is Chrome-specific, Chrome's built-in OpenType Sanitizer (OTS) rejects fonts that contain non-standard or unsupported OpenType tables (in this case
vheawith an unrecognised version0x10001). Safari is more permissive and loads the same font without issue.The failure happens inside
loadFontFaceInBrowser()whenFontFace.load()throws aSyntaxError. Since this function is only responsible for loading the font into the browser for preview purposes, the error propagates as an unhandled rejection and blocks the entire upload, even though the server-side installation would otherwise succeed.The fix I'm working on wraps
FontFace.load()in a try-catch directly insideloadFontFaceInBrowser: if Chrome's OTS rejects the font, the function returns silently and the install proceeds normally. The font won't preview in the editor canvas on Chrome, but it installs and is usable in the theme. Compliant fonts are unaffected.Will be raising the PR soon.
t-hamano commentedon Mar 9, 2026
Instead of masking the error, should we inform the user about the error and encourage them to fix the invalid data in the font itself?
Ayushinag commentedon Apr 15, 2026
Hi, I tried another font-family TTF file, and it worked properly—the font was uploaded successfully. It seems that only this particular TTF file is not uploading as a font family.