Not enough physical memory is available to power on this virtual machine with its configured settings.
To fix this problem, decrease the memory size of this virtual machine to 616 MB, increase the amount of physical memory for all virtual machines to 981 MB, or adjust the additional memory settings to allow more virtual machine memory to be swapped.
It is possible that native applications and/or services have locked down memory which could be preventing the virtual machine from launching. Shutting down unnecessary applications or services may free enough memory to launch this virtual machine.
If you were able to power on this virtual machine on this host computer in the past, try rebooting the host computer. Rebooting may allow you to use slightly more host memory to run virtual machines.