Imgur: Failed to renew auth token

Dropzone Version 3.5.4 (855)
OS X 10.10.5

debug console:
ACTION: "/Applications/Dropzone 3.app/Contents/Actions/Imgur.dzbundle"
EVENT: "dragged"
VARIABLE: "account_username" "user"
VARIABLE: "dragged_type" "files"
VARIABLE: "app_version" "3.5.4"
VARIABLE: "client_id" "••••"
VARIABLE: "refresh_token" "••••"
VARIABLE: "client_secret" "••••"
VARIABLE: "access_token" "••••"
VARIABLE: "support_folder" "/Users/user/Library/Application Support/Dropzone 3"
ITEMS: "/the/path/to/ImageName.png"

Determinate: 0
Error_Title: Failed to renew auth token
Error: Try removing and readding your Imgur account.

Debug Info: Invalid JSON received {"data"=>{"error"=>"Imgur is temporarily over capacity. Please try again later."}, "success"=>false, "status"=>500}

I guess it is because dropzone failed to detect my proxy setting.