Please provide version of your Avamar & storage info in brief.

As brn_lewisk said in the other thread:

Incidentally, Error 30901 is a TimeOut Start - that means the backup did not start before the backup window closed.  There could lots of reasons - you'll need to investigate a bit further.

These backups are queued up and not getting a chance to run before their scheduled window expires. You'll have to investigate the reason for that. Backups will stay queued as long as they are missing some required resource. It could be an Avamar stream, a DD stream, a slot on a VMware Image proxy, etc.

using avamar (avamar enterprise manager 7.1.2) , Vplex local which is connected to vnx 5700 (unified)

first thing would be to filter by server name.

is there another job on the same server still running at the time your backup window closed?

Example

server VSS backup running  (may or may not be processing anything - could be hung)

server file system backup queued

backup window closes

VSS backup fails

file system backup has a failed to start

could also be you don't have enough proxies or other resources.

you should look at the job BEFORE it fails to see if you can figure out what it is waiting for.