Seaquel
MySQL error code

MySQL error 3903

MySQL server error 3903 is ER_INVALID_JSON_VALUE_FOR_FUNC_INDEX, reported with SQLSTATE 22018.

Invalid JSON value for CAST for functional index '%s'.
Error3903
NameER_INVALID_JSON_VALUE_FOR_FUNC_INDEX
SQLSTATE22018
GroupServer errors

In other databases

Source: MySQL 8.4 Error Reference