The start of the Openfire log shows that you did start Openfire two times (Le processus ne peut pas accéder au fichier car un autre processus en a verrouillé une partie : C:\Program Files (x86)\Openfire\embedded-db\openfire.lck) So the log is quite useless. Please stop Openfire and make sure that it is really stopped (no java processes in Task manager).
Do you run the Openfire service or do you start it in foreground?
@"javax.net.ssl.SSLException: Unrecognized SSL message, plaintext connection?"
Do you use the normal 5222 port or the old SSL port 5223?
It would be nice if you could disable port 5223 in Openfire to make sure that all clients connect to port 5222.
Do you have this problem also with ASCII only accounts and password (e.g. "test" and "test")? Actually UTF-8 user names and passwords should work.
PS: It really helps to get the Openfire logs (debug+info+warn+error) and the Spark log of only one failed login - the more log lines you provide the less likely it is that one will find the problem.