Linux VM does not start

[Beans3]

I am hoping someone can help.

After attempting to transfer some video files from my VM to external storage by USB my VM froze - just a blank screen. Now will not start despite no external USB connection.

Attached is a log after I shut down the VM.

Here's some info about my host:

Processor -
¥ 3.1GHz dual-core Intel Core i5, Turbo Boost up to 3.5GHz, with 64MB of eDRAM
Configurable to 3.3GHz dual-core Intel Core i5, Turbo Boost up to 3.7GHz, with 64MB of eDRAM; or 3.5GHz dual-core Intel Core i7, Turbo Boost up to 4.0GHz, with 64MB of eDRAM
Storage1
¥ 256GB
256GB PCIe-based onboard SSD
Configurable to 512GB or 1TB SSD
¥ 512GB
512GB PCIe-based onboard SSD
Configurable to 1TB SSD
Memory
¥ 8GB of 2133MHz LPDDR3 onboard memory
Configurable to 16GB of memory
Graphics
¥ Intel Iris Plus Graphics 650

and VM:

operating system - Ubuntu (64-bit)
Base memory - 2458 mb
Boot order - floppy, optical, hard disk
Acceleration - VT-x/AMD-V, Nested Paging, KVM Paravirtualisation
Display Video memory - 128MB
Acceleration - 3D
Remote Desktop Server - Disabled
Video capture - Disabled

Audio host driver - CoreAudio
Controller - ICH AC97

Storage
Controller - IDE
IDE Secondary Master (Optical Drive) : Empty
Controller- SATA
SATA Port: Linux download 2.vdi (Normal, 95.15GB)

USB
USB controller - xHCI
Device Filters: 3(3 active)
Shared folders: 1

[Beans3]

I think I found the problem - I had just run out of allotted memory in the VM. Once I'd freed up some memory it became stable again.