java.lang.NoSuchMethodError: org.jivesoftware.util.JiveGlobals.isPropertyEncrypted(Ljava/lang/String;)Z
Not sure, but maybe you have added or edited some system property after upgrading to 3.9.2/3.9.3? I think property encrypting was introduced in 3.9.2 and 3.9.1 probably can't understand such entry and throws an exception. As there is a bug which always encrypt new properties even if you chose not, i don't see another option other than upgrade to 3.9.3, remove the encrypted system property, downgrade to 3.9.1, add the property back. Probably can also be done by directly editing the database, but i'm not good at that.