Custom WebTemplate in SharePoint 2013

Hi,

Tried to create the custom WebTemplate and provision through Visual Studio. Works perfectly in SharePoint 2010 dev environment, but when Deploying the 2013 the WebTemplate does not appear in the list of available templates.

Nothing special in logs, no errors when deploying the solution.

My goal is to provision via sandboxed solution but I have tried both farm and sandboxed deployment -  didn't work.

Could no find any articles about WebTemplate element changes.

Any ideas? Thanks!