Failed to retrieve extension data.Server not responding site

Whenever I add or remove or upgrade an extension, I see this in red at the bottom of the screen.
If I refresh, the task actually works. So it’s not stopping anything - just kind of annoying.
Running XWiki 10.9 on Ubuntu in SSL with NGINX reverse proxy and a Docker container.

Can you check e.g. with the Browser “Developer Tools” -> Network tab which response from the server might cause this behaviour? There should be something in the “XHR” section that returns with a return code different from 200; if it is, it is likely to be the culprit.
The server response of that request might contain an error message that might help to nail down the problem.

I see a 302 error. The requested URL was:

Request URL:

I fixed this by adding the following to the "HTTP Meta Info " under the “Presentation” section of “Look and Feel”

<meta http-equiv="Content-Security-Policy" content="upgrade-insecure-requests"> 

For I saw this in the Chrome console:

“This request has been blocked; the content must be served over HTTPS.”


@vmassol . Do you know what file this would need to be hard coded into so that I dont get this error on a fresh install? Im running into this error just trying to install the Standard Flavor during the initialization.
<meta http-equiv="Content-Security-Policy" content="upgrade-insecure-requests">


Good Job, thank you.


I have the same issue, i can’t upgrade any extention : [Failed to retrieve extension data.Server not responding]
I don’t found the file to add

Anyone can help me to solve this ?

I also got this issue in the distribution wizard. I want to update from 10.9 to 10.10 and in the wizard I want to update the Extensions and that’s the error that is shown.