In the Javascript console, VK is throwing the following error:
Uncaught Error: No owner_id passed
at Object.VK.Widgets.Subscribe (openapi.js:1657)
at (index):3416
It looks like there's both a documentation issue with our button and a change in how the VK subscribe button works.
Can you update your tag to add the user or group link that you want the subscribe button to be for, like:
{SCVkSubscribe type=user link=http://vk.com/link-to-your-profile}
If you're setting up a subscription to a group, change the type to group. However, I think a code change may be necessary for the group link to work, but please try.
I'm also seeing a couple areas in the code that we could improve efficiency for that widget. Let us know how the above goes and we can help make sure that widget works properly for you.
Thanks,
Alex