ye betul - cache ade wipe - cache kena wipe juge.

Ok try flash the twrp again - this time using the zip file - previously you install via Odin right?
The message should be - Backup Successful .

I think i know why your backup failed - what are the radio button (the partitions button) that you ticked in the backup column?

ha ha - you should not ticked cache 
By the way you may download twrp zip

Ok now go and find the previous backup file in the TWRP folder - TWRP - BACKUPS - another folder - another folder with the date that you backup (cut and paste this file some where else)

download the twrp 2.7.0.0 zip file to your s3 device - reboot your phone to recovery mode and flash that twrp 2.7.0.0 zip - reboot system

Ok take a break - go take lunch and perform Zohor first 

At least your device is still alive - cool brader 

After lunch - go here and read carefully

cabut bateri saja la..

Never come across this kind of issue in my recovery - got issue with 2.6xx but after migrated to 2.7.0.0 no issue at all.
It's time to install another recovery bro.

he just said it.. twrp 2.7.0.0.

deleted.