During insert, update or delete of records to a table that is being reorganized, you encounter this error :
Error(6-14) Non-specific database error: ORA-20509: Table unavailable - live reorg in progress
Table switch is using T-lock style.
The error is normal, because during t-lock switch style, the table is not available for a short period of time. T-lock is a trigger that will rollback the application update whilst the switch is occurring.
If possible you should take the following into account;
Use online switch unless there are datatypes or restrictions that stop you using online.
Use a manually approved switch and wait for a quiet period, or an automatic switch set to a time where the database should be quiet.