Control-M: 23_EUQ - Event: JOB NOT OK App: BARN-IS-BI-DEV-BDB Job: RMAN-INCREMENTAL-BACKUP Folder: 9EUDV23_SUS-DATABASE-BW_CS
Full backup is currently running in BDB (Time : 17:20 CET). 
that is why the incremental backup failed. 
once the full backup is completed The incremental backup will be triggered at 7:50 CET.