Comment 0 for bug 1619341

Detailed bug description:

Deploy an env with DVS plugin related to 9.x
Go to the "Workflows" tab and try to download YAML
for the "plugin (Neutron VMware DVS ML2 plugin)" I saw the error message:

File Download Error
A server error has occurred. Please contact your system administrator.

but JSON file was downloaded successfully

Description of the environment:

9.x snapshot# 197

Scenario:
    1. Upload plugins to the master node
    2. Install plugin.
    3. Create a new environment with following parameters:
        * Compute: KVM/QEMU with vCenter
        * Networking: Neutron with VLAN segmentation
        * Storage: default
        * Additional services: default
    4. Add 1 node with controller role.
    5. Configure interfaces on nodes.
    6. Configure network settings.
    7. Enable and configure DVS plugin.
    8 Configure VMware vCenter Settings.
       Add 1 vSphere clusters and configure Nova Compute instances
       on controllers.
    9. Deploy the cluster.
    10. Run OSTF.