If your web application uses assetic and you require to use filters with it, you would have to find a way to do so outside the server. Our Shared Hosting service doesn’t provide the necessary tools for the most used filters, for example Java for the Yui Compressor filter or Ruby.
These are some workarounds for this:
Assetic Web Service: There is a free web service provided by ServerGrove, which allows you to generate your assets just by calling the API. It is available at assetic.servergrove.com and you can find out more at https://github.com/servergrove/assetic-web-api
Local: Another possible solution is to dump your assets in your local computer and upload them along with your app.
VPS: The latest option would be to upgrade to a VPS plan, which allows to install and configure any software you may require, as you have full root access to the server.