DSNE124E DATA SET `data-set-name`, MEMBER `member-name` IN USE, TRY LATER

Explanation
 The member contained in 'data-set-name' is currently
in use. This message is normally issued when another user is updating
the specified member.

System action
 The TSO attachment facility is ready for more
input.

User response
 Wait until the member is available and reissue
your DCLGEN request.