Attachment thumbnails disappear after uploading a new image

[Luiza Salim]

Hello,

I am experiencing a bug in Trello.

After uploading or pasting a new image into any card, all image attachments across the board stop displaying their thumbnail previews and are shown only as "PNG".

At the same time, the "Remove cover" option disappears from cards where the first attachment automatically became the cover.

If I refresh the page, all thumbnails appear normally again. However, as soon as I upload another image, the issue immediately returns.

I have already tested:

• Google Chrome
• Microsoft Edge
• Incognito mode
• The upload requests complete successfully (HTTP 200 in DevTools Network)

This seems to be a client-side rendering issue rather than an upload failure.

Could you please investigate?

[Rishabh S]

Hi @Luiza Salim , :)
Hope you are doing well,
Welcome to the community!!

thanks for the detailed report and for the troubleshooting steps you've already run through!
I checked this on my end, but was not able to reproduce it.

A few things worth trying:

1. Check your upload method - Could you let us know how you're attaching the images? For example, are you dragging and dropping onto the card, using Add > Attachments > Select a file, pasting directly, or using another method? This helps narrow down whether the issue is tied to a specific upload path.

2. Hard refresh - Try Ctrl/Cmd + Shift + R right after uploading to force a cache-clear reload and see if the thumbnails persist.

If the issue continues regardless of browser or upload method, it'd be really helpful to know:

• Your browser name and version

• Whether this happens on the Trello desktop app as well, or only in the browser

• Approximately when you first noticed this behaviour

Thanks.