500 Internal Server Error on vagrant up

[tryfan]

I'm getting a 500 Internal Server Error from proxmox 3.2-4. Test user is set up to be an Administrator for testing.

Logs are showing the following:
10.0.201.1 - root@pam [29/Jul/2014:14:32:26 -0400] "GET /api2/json/cluster/resources?type=vm HTTP/1.1" 200 2795
10.0.201.1 - root@pam [29/Jul/2014:14:32:26 -0400] "POST /api2/json/nodes/prox4/openvz HTTP/1.1" 500 13

vagrant responds with:
Bringing machine 'testbox' up with 'proxmox' provider...
==> testbox: Creating the virtual machine...
Unable to create the virtual machine!

Cause: 500 Internal Server Error

Vagrantfile:
Vagrant.configure('2') do |config|

config.vm.provider :proxmox do |proxmox|
    proxmox.endpoint = 'https://prox1:8006/api2/json'
    proxmox.user_name = 'admin@pam'
    proxmox.password = 'pass'
    proxmox.vm_id_range = 900..910
    proxmox.vm_name_prefix = 'vagrant_'
    proxmox.os_template = 'local:vztmpl/ubuntu-14.04-x86_64.tar.gz'
    proxmox.vm_memory = 512
    proxmox.task_timeout = 60
    proxmox.task_status_check_interval = 1
end

config.vm.define :box, primary: true do |box|
    box.vm.box = 'testbox'
end

end

[sebrem]

Please check if the template file name is correct. Probably using the latest version v0.0.5 will issue a better error message.