@sunqi
sudo apt-get install -y python-software-properties
sudo add-apt-repository -y ppa:rwky/redis
sudo apt-get update
sudo apt-get install -y redis-server
The -y saves you having to confirm when it asks if you want to install.
Same error with persona theme and nodebb 0.9.3.
[edit] the error
https://le.club.systemes.sonores.rocks/api/topic/thumb/upload
500 Internal Server Error
w and h must be numbers
