I upgrade from version 2.9 to the latest current version and the process went well however some avatars are not showing up.
Hi Islam 
Do you notice a pattern in the avatar that doesn’t appear (like only customized avatars for example)?
Are there any errors in the JS console in your browser’s development tools?
Hello Coin,
There is no errors in the JS console.
I cannot identify if there is a pattern because there are thousands of users.
I ran the command rake avatars:refresh but it didn’t help.
Requests like /user_avatar and /admin/reports/bulk fails with HTTP 504.
I’m running 3.1.0.beta3 and this issue happened after the upgrade.