Thanks for your quick reply.
That's right, I installed the Java Installer Package from the Community and it installed the version 13. Now FileBot does not display the error message anymore.

Thanks !!

Hi,

I installed Java8 on my Synology NAS :

David@David_Serveur:/usr/local/bin$ find / -name java 2>/dev/null
/volume1/@appstore/Java8/j2sdk-image/jre/bin/java
/volume1/@appstore/Java8/j2sdk-image/bin/java

When I launch FileBot, it tells me :

$ filebot -version
/usr/local/bin/filebot: line 67 ...