[Snapshot Pro] Managed Snapshot not working

I\'ve noticed that my managed snapshots don\'t seem to be working or completing.

The following is shown inside the log...

[snapshot][2018-02-21 01:29:49][Warning] Unable to perform requested system backup, proceeding with builtin
[snapshot][2018-02-21 01:29:55][Warning] Unable to perform requested system backup, proceeding with builtin
[snapshot][2018-02-21 01:29:57][Warning] Unable to perform requested system backup, proceeding with builtin
[snapshot][2018-02-21 01:30:06][Warning] Unable to perform requested system backup, proceeding with builtin
[snapshot][2018-02-21 01:30:07][Warning] Unable to perform requested system backup, proceeding with builtin
[snapshot][2018-02-21 01:30:19][Warning] Unable to perform requested system backup, proceeding with builtin
[snapshot][2018-02-21 01:30:19][Warning] Unable to perform requested system backup, proceeding with builtin
[snapshot][2018-02-21 01:30:24][Warning] Unable to perform requested system backup, proceeding with builtin
[snapshot][2018-02-21 01:30:24][Warning] Unable to perform requested system backup, proceeding with builtin
[snapshot][2018-02-21 01:30:31][Warning] Unable to perform requested system backup, proceeding with builtin
[snapshot][2018-02-21 01:30:33][Warning] Unable to perform requested system backup, proceeding with builtin
[snapshot][2018-02-21 01:30:39][Warning] Unable to perform requested system backup, proceeding with builtin
[snapshot][2018-02-21 01:30:41][Error] Error processing manual backup: unknown:unknown
[snapshot][2018-02-21 01:30:46][Warning] Unable to perform requested system backup, proceeding with builtin
[snapshot][2018-02-21 01:30:53][Warning] Unable to perform requested system backup, proceeding with builtin
[snapshot][2018-02-21 01:30:58][Warning] Unable to perform requested system backup, proceeding with builtin
[snapshot][2018-02-21 01:31:10][Warning] Unable to perform requested system backup, proceeding with builtin

This is my own AWS server which I have full control of. I pass all the requirements for managed backups according to the check list. Anything in particular I should adding/changing to make this work 100% of the time?