10000454 
Message
Closing an activity is irreversible (closed activities cannot be modified). Continue?
Diagnosis
While modifying an existing activity, on the General tab, you have selected the Closed option and have chosen Update.
Procedure
Do one of the following:
To close the activity, choose Yes.
CautionSetting an activity as Closed is irreversible.
End of the caution.To save the activity without closing it, choose No.