This error can be received when the HCC tables are queried or processed on databases in Oracle database 18.104.22.168 and above. It is seen because of bug number 24818566. The following patch can be applied for this bug, or it may be considered upgrading. The problem is fixed in version 22.214.171.124.
SQLLOAD FAILED WITH ORA-600 [KDZA_CHECK_EQ NOT IN DICTIONARY] (Patch 24818566)
There are no patches for 126.96.36.199. To fix the problem, the version needs to be upgraded.