All the tasks fail with: "failed to find virtual server by uuid: find virtual server by uuid "<UUID>": invalid argument"

Symptoms 

SVM_ERROR: All the tasks fail with: "failed to find virtual server by uuid: find virtual server by uuid "<UUID>": invalid argument"

Cause

SolusVM 2 communication is interrupted with KVM handler.

Resolution

# systemctl restart solus-agent
# systemctl restart libvirtd

These commands do not impact the VPS's, they only restart the SolusVM 2 service and KVM handler service.