I’m using Cloudflare R2, by the way, and it works great, except for this issue. The only issue I encounter is images attached on chat; the thumbnail is broken. Clicking the thumbnail loads the full images correctly. The thumbnail URL that is broken is https://bucket.xxxxxx.r2.cloudflarestorage.com/optimized/1X/xxxxx_2_690x201.png Which, when accessed directly, returns: InvalidArgument Authorization Thumbnail correct URL should be: https://r2.discourse.com/optimized/1X/xxxxx_2_690x201.png The full image URL is https://r2.discourse.com/original/1X/xxxxx.png It seems for image thumbnails it uses the Cloudflare R2 endpoint API domain for some reason. My app.yml config: ## Cloudflare R2 DISCOURSE_USE_S3: true DISCOURSE_S3_REGION: auto DISCOURSE_S3_ACCESS_KEY_ID: xxxxx DISCOURSE_S3_SECRET_ACCESS_KEY: xxxxx DISCOURSE_S3_CDN_URL: https://r2.discourse.com DISCOURSE_S3_BUCKET: bucket DISCOURSE_S3_ENDPOINT: https://xxxxx.r2.cloudflarestorage.com DISCOURSE_S3_INSTALL_CORS_RULE: false DISCOURSE_S3_BACKUP_BUCKET: bucket/backups DISCOURSE_BACKUP_LOCATION: s3 Thanks, and I apologize for being a newbie on this thing.

The same issue happens for newly installed themes; the thumbnail is broken and points to https://bucket.xxxxx.r2.cloudflarestorage.com/original/1X/xxxxx.png

Now that I am too utilizing chat I noticed this error too. Thumbnail is indeed broken here and when I click the broken image it shows the image in a “popup” as it should. [image] The url for the broken image is indeed not the CDN url. Broken url (redacted some bits) https://BUCKET.REDACTED.eu.r2.cloudflarestorage.com/optimized/1X/21ec5908f511bdc9fa7970107b40fad3f008327c_2_500x500.jpeg Working url https://cdn.pelittaa.fi/optimized/1X/21ec5908f511bdc9fa7970107b40fad3f008327c_2_500x500.jpeg

This seems to be a “fix” for this issue, or at least a workaround to get this working for now. Ping @Justin_Hamilton [image] Cloudflare R2 Image URL Display Issue: Detailed Explanation and Fix Bug Problem Description We’ve recently noticed an issue with image display on the forum, specifically: Image thumbnails are not displaying correctly. Clicking on the images displays the full-size image correctly. The browser’s developer tools show incorrect image URLs. [The image shows a chat interface with a conversation in Chinese, in which a user is asking about common questions or guesses regarding a URL screenshot, as indicated by dialogue bubbles and a red arrow. (由 AI 生成标题)] After invest…

Image thumbnail is broken on chat messages when using Cloudflare R2

Product Support

Justin_Hamilton (Justin Hamilton) February 11, 2026, 6:20pm 3

Did you ever find a resolution to this? I also have this issue on my own instance.

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Image thumbnail is broken on chat messages when using Cloudflare R2

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