xenserver 7.4 > 7.6 Live Migration Failed

VM was moved using live migration:

Migration appeared to have been completed (could see the new VM on the new server, VM on old server went in a suspended state) - Moments later the process failed, VM on new server dissapeared and VM was still in suspended state on old server. Message in Xencenter:

"Failed","Migrating VM 'code.intelli.host' from 'Abi' to 'dilbert'
Internal error: Storage_interface.Does_not_exist(_)
Time: 00:09:48","dilbert","Mar 25, 2019 3:47 PM"

When tried to start the suspended VM, the following error occured:

"Failed","Resuming VM 'code.intelli.host'
VM cannot be resumed because it has no suspend VDI","Abi","Mar 25, 2019 4:03 PM"

Moments later the VM "went off" and I was able to start it again on the old server. This could have been problematic if the VM was deleted off the old server (or possibly storage was deleted).

Although I was able to recover, this can be troublesome as a simple migration (done through a GUI with no other human intervention) should not break like this. I also now have a 40GB VDI on my storage repo that cannot be removed. I dont particularly know how to remove it.

What logs can be provided to help determine the cause and if this is related to a bug? I am only opening this as a bug as I saw numerous posts going back to 2017 related to the same issue, and it was flagged at the time as a bug. 

I have attached the SMlogs on the new server which occured during the time of failure.