All you need to do is select your Add-on in the Workshop Publisher Menu and do an 'Update Item' and re-upload your content. This update removed the VPK requirement for Add-ons to solve various engine issues. Please note that if you have a Workshop Add-on (not 'Item Replacements') currently active in the Synergy Workshop you need to re-update it.
If you find any issues with this update, please post the details in the forums and I'll be sure to check it out. Heya folks, here is another update for ya with various internal improvements.
