===== [V8] ISSUE: Unable to do backup (Failed to download v6 index) when performing backup after upgrading AhsayCBS to 8.1 or above ===== Article ID: 8058
Reviewed: 2019-06-15

Product Version:
AhsayACB / AhsayOBM: 8.1 to 8.x
OS: All platforms ===== Problem Description ===== After upgrading the backup server from version 6 to 8.1 or above, the following error message is displayed when performing a backup of any type:

No.	Type	Timestamp	Log
*	info	YYYY/MM/DD hh:mm:ss	...
*	...	...	Downloading server file list...
*	erro	YYYY/MM/DD hh:mm:ss	Unable to do backup, Error= [MigrateV6Index.downloadV6Index] Failed to download v6 index
*	...	...	...
*	erro	...	null

===== Cause ===== This issue can occurs if the index file of the corresponding backup set is corrupted before the upgrade. The corrupted index file cannot be retrieved for the sub-sequence backup jobs after the upgrade. ===== Resolution ===== To resolve the issue, perform a single backup set rebuild for the corresponding backup set, and then perform another backup job afterward.

Refer to the following article for instruction on how to perform a backup set rebuild:

FAQ: How to run a single backup set rebuild for legacy backup set created in version 6? ===== Keywords ===== index, corrupted, migrate, migration, upgrade, patch