Unable to take snapshots even after powering off VM

I inherited an OpenNebula setup created by another administrator, and I’m not very familiar with it at all. I need to take a snapshot of one of the VMs it hosts. Despite being in the POWEROFF state, the “Take snapshot” button is still greyed out. I don’t know where to begin troubleshooting this problem.

Versions of the related components and OS (frontend, hypervisors, VMs): Debian 9 Stretch, OpenNebula 5.4.13-1, Sunstone 5.4.13-1.

Steps to reproduce:

  1. Power off the VM by clicking its entry in the VM list, then clicking the power symbol button and clicking “Power Off”.
  2. Attempt to take a snapshot by clicking the VM’s entry in the VM list, going to the “Snapshots” tab and seeing that the “Take snapshot” button is greyed out.

Current results: Unable to click the “Take snapshot” button.

Expected results: Able to click the “Take snapshot” button and take a snapshot of the VM.