Time-to-time I am hitting the wall with this, even with 100+ VM sites in my portfolio, and parts of VM core having my signature. Here are few tricks wich usually solves the problem.
The main culprit is generally Akeeba Backup - more precisely the System Restore Points plugin.
If you don't want to touch your Akeeba settings (or not sure about the cause) you can try to avoid use of the live update button - a token error comes from the Akeeba live update code with some servers, or from using the Akeeba's System Restore Points setting where Backup Pro is installed.
In this case you can download the latest VirtueMart FULL install package, and install it from the Joomla component installer directly.
If that leads you to the same result, then you need to make your hands dirty: you can try to check, if you have that plugin installed and active. If yes, you probably can solve the problem by temporarly disable the plugin.
If that still does not works, you need to dig even deeper, go to the official VirtueMart downloads site, and locate the patch package wich suits you:
Unzip/untar the files locally, and using your preferred FTP client upload the files to your server, overwrite the files found there with the ones in the package.
Then access VirtueMart's admin interface, go to the Configuration page, check and doublecheck the settings, and save the configuration.
This would solve the problem - ant the next update should be painless.
Of course, do some backups.... Preferably BEFORE your actions potentially ruin your site ;) And use, also preferably Akeeba Backup for that!!!