# Can't generate user avatars when moving to new server because extension is "unknown" **URL:** \ **Category:** Bug\ **Created:** [October 26, 2021, 2:35pm UTC](https://meta.discourse.org/t/cant-generate-user-avatars-when-moving-to-new-server-because-extension-is-unknown/207134 "2021-10-26T14:35:36Z")\ **Posts on this page:** 1\ **Showing post:** 1
**Author:** ![pfaffman](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/pfaffman/32/120154_2.png) [@pfaffman](https://meta.discourse.org/u/pfaffman)\ **Post date:** [October 26, 2021, 2:35pm UTC](https://meta.discourse.org/t/cant-generate-user-avatars-when-moving-to-new-server-because-extension-is-unknown/207134/1 "2021-10-26T14:35:36Z")
EDIT: I’m reclassifying this as a bug, so that someone who understands this better than I can take a look at it. a bunch of uploads had “unknown” as the extension. This means that it’s impossible to generate thumbnails. I think this happened when moving a backup to a new site and then needed to regenerate the thumbnails. I think what should happen when you try to generate thumbnails and the extension is ‘unknown’ is to replace the extension, something like ``` upload.extension = upload.original_filename.split('.').last ``` It seems like if this were done somewhere that I’d not have spent 4 hours on this. Wait. This looks like the problem. Why return `false` rather than get the extension from the filename? > ## Gory details follow. I moved a site from `/community` to `community.example.com` by doing a backup and restore. I fixed the uploads with a ``` RAILS_ENV=production bundle exec script/discourse remap '/community/uploads' '/uploads' ``` But the avatars are still the Gray Man. When I look at `user.user_avatar.custom_upload.url` and paste that URL into the browser, I get the desired avatar. It seems like I need to “rebake” the users. I thought that perhaps a ``` rake avatars:refresh ``` or ``` rake avatars:clean ``` might fix it, but no joy. What am I missing? --- _[View the full topic](https://meta.discourse.org/t/cant-generate-user-avatars-when-moving-to-new-server-because-extension-is-unknown/207134)._