If you boot your Virtual Canary template, you will not be able to use it to create new Virtual Canaries. (This makes sense, because now, every time your image boots, it will want to boot with its previous personality.) There are however a couple ways to rectify this.
The first, and simplest, is to download the template again. You can do so by following the steps in How do I setup a Virtual Canary.
The second is to use the existing image, copy it, and then make use of the 'factory reset' functionality:
Step 1: Locate your Virtual Canary password
In order to login to your Virtual Canary configuration you will need the password associated with the template. You can see this password by logging in to your console, going to 'Setup' and then navigating to 'Virtual Canary'.
Each version of Virtual Canary has it's own password. If your console has multiple versions, simply use the password that relates to the template version you are trying to reset.
Step 2: Boot your image
Start your Virtual Canary and wait for it to finish booting.
Step 3: Login to your Virtual Canary
Using the displayed username on the login screen, and the password obtained from your console, login to your Canary.
Step 4: Factory reset the bird
Navigate to 'Factory Reset'.
Confirm the dialog asking if you are sure you want to factory reset.
Step 5: Wait for the bird to reboot
Once the image reboots, it will now register as a new Canary, follow the steps in How do I setup a Virtual Canary and you can configure it as you wish.