I get error message when I try to save the data after zone reactivation in FLUENT. Why?
If you initialize the solution after deactivating the zone, you will get error when you try to save the data file. You are not able to write the data because there is no data present for the reactivated zone.
If you initialize the solution before deactivating the zone, all the zone will have data, and you will be able to write the data after reactivation.
If you have not initialized the data before deactivation, the zone will not have any data. So you need to run one iteration/ time step after activating the zone ( or initialize the solution) for writing the data.
If the interface exists while deactivating the zone, then the interface will be recreated automatically with the zone reactivation.