RMAN-03002: failure of backup command

Hi All

I am running a 12.1.0.2 DB Version on Windows 2012R2 - 64bits.

I use to perform the backups with the below script and today I got the error below... I launched the backup again and it worked, but I would like to know what could have happen and if possible avoid it.

RMAN> run {

2>  allocate channel t1 type disk;

3>  allocate channel t2 type disk;

4>  allocate channel t3 type disk;

5>  allocate channel t4 type disk;

6>  allocate channel t5 type disk;

7>  allocate channel t6 type disk;

8>

9> crosscheck archivelog all;

10> CROSSCHECK BACKUP;

11>

12>  backup as compressed backupset incremental level = 1 CUMULATIVE TAG 'L1_Bkup'