Error upgrading kayako 4.92.2 to 4.92.4

Does anyone have an idea why i get this error?

Version php: 5.6.36
Version apache: 2.4.33

Uncaught Exception
Class \Tickets\Models\Bayesian\SWIFT_Bayesian_Exception does not exist (-1) in ./__swift/library/Setup/class.SWIFT_SetupDatabase.php:1350
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#0 ./__swift/library/Setup/class.SWIFT_SetupDatabase.php(1350): ReflectionClass->__construct('\\Tickets\\Models...')...

Error upgrading kayako 4.92.2 to 4.92.4