There are a number of common problems after initial flashing of your quad with the Silverware firmware. Be assured that unless the flashing failed or you modified values or code before flashing, then the Silverware firmware is unlikely to be the issue. If flashing failed you'll see the error when flashing so you'll already know that's the problem.

Here is a list of common problems:

1. Propellers are incorrectly attached - with the quad top facing up, facing forward and starting with the top left motor and going clockwise, the propellers should be B, A, B, A like shown in the image below:
   
   
2. Motors/propellers are obstructed in some way. Check each propeller is spinning freely when flicked with your finger. Any that do not spin freely are at issue. Check that these are not pressed too firmly causing friction between the frame and the propeller. Also check for foreign objects such as hair or cobwebs, etc.
3. You modified some settings in the silverware firmware. If you've modified any properties in the silverware firmware or could have accidentally then download a fresh copy of the firmware and flash your quad again to eliminate this being an issue.