from what I recall, it says this: "Imprisons the target temporarily behind a white magic curtain, preventing them from moving. While in this state, the target cannot take damage other than ghost property attacks.
When White Imprison ends the target takes 2000 damage. You can cast this skill on yourself but it will last 20% shorter and take 2000 damage when it ends." It says it prevents them from moving, so wouldn't that go under the category as not being able to cast skills? Of course, Im not the admin, and Im also can't say you're wrong, as I have not seen the problem myself. If it literally puts you in silence status, then the best I can suggest is get a Munak Card. if it just acts as silence, then there is nothing I can do until I see the situation for myself. Hope I helped.
With all due respect,
~Flirachi