Oracle Error Message
ORA-56920: a prepare or upgrade window or an on-demand or datapump-job loading of a secondary time zone data file is in an active state
Reason for the Error
A prepare or upgrade window was started or an on-demand or datapump-job loading of a secondary time zone data file was done.
Solution
Make sure there is no active prepare or upgrade window and no active on-demand or datapump-job loading of a secondary time zone data file.