MariaDB server can't join Galera cluster after restart

Hi,

We have configured a cluster of 4 mariaDB servers with Galera (with the SST xtrabackup-v2).
We had some issue when joining the cluster with one node.

Our problem is that when we launch the mysql process it tried to sync with the cluster. It clean the /var/lib/mysql folder and sync all data from an other node.
Everything goes well until it tries to launch the process itself (at the end of the joining process).
We have some logs that I provide in attachments (maria.log).

So it seems that it does not found one file and when we try to start again the process it fails and sync from the begining.

Maybe we forgot something (obvious ?) in the configuration but we can't find it.

If you can help us it would be great.

Thanks.
Regards,
Thomas.