Java error upgrading to Lucee 6

Updated an app from 5.4 to 6.0.451 beta 2. Now am getting this error. Site will not load.

lucee.runtime.type.dt.DateTimeImpl; local class incompatible: stream classdesc serialVersionUID = 8549854336376075433, local class serialVersionUID = -8364119142383391118

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OS: Windows 11
Java Version: 15.0.1 (Oracle Corporation) 64bit
Tomcat Version: Apache Tomcat/9.0.75
Lucee Version: 6.0.0.451-BETA