Very simple bug:
The Scribing skill "Vault" does not work while under the effects of a Negate, despite being a Stamina-costing ability that should not be suppressed.
You can see this demonstrated
here.
The skill is not greyed-out like Magicka and ultimates are but the skill itself does not complete after casting. You can see the animation begin and then be immediately aborted. I attempt to cast it 3 different times in the video and they all demonstrate the same abortive behavior.
My guess is that there is some invisible Spell-type coded effect (similar to setting up a piece of Siege equipment) that is a component of Vault and that is unintentionally suppressed by Silence. This is clearly a bug, though, and should be fixed.