Upgrade from 11.2.0.4 to 12c DBUA error

Hi everyone,

I have a problem starting upgrade of 11.2.0.4 database to 12c.

When i start dbua tool i get the following error:

[pool-1-thread-1] [ 2017-05-30 23:32:00.609 CEST ] [SQLEngine.initialize:399]  Starting Reader Thread...

[pool-1-thread-1] [ 2017-05-30 23:32:01.637 CEST ] [OracleHome.initOptionsStopOnError:1370]  executing: startup nomount pfile='/apps/DEV/db/tech_st/12.1.0/dbs/initDBUA3200497.ora'

[pool-1-thread-1] [ 2017-05-30 23:32:05.838 CEST ] [SQLEngine.done:2278]  Done called

[pool-1-thread-1] [ 2017-05-30 23:32:05.839 CEST ] [OracleHome.initOptionsStopOnError:1379]  ORA-00600: internal error code, arguments: [16305], [], [], [], [], [], [], [], [], [], [], []

[pool-1-thread-1] [ 2017-05-30 23:32:05.839 CEST ] [OracleHome.initOptionsStopOnError:1380]  ORA-00600: internal error code, arguments: [16305], [], [], [], [], [], [], [], [], [], [], []

oracle.sysman.assistants.util.sqlEngine.SQLEngine.executeImpl(SQLEngine.java:1739)

oracle.sysman.assistants.util.sqlEngine.SQLEngine.executeSql(SQLEngine.java:2014)