You've not really described the problem very well here at all.
Luckily for you, I've had this a couple of times too:
Basically, what happens is, when you use an LWC command and click on a protection, the system sends that red message back instead of performing what action you want.
IE: If you do /cinfo and click a door, it should tell you info about the door, but can sometimes tell you that you have another action pending for some reason.
Just keep trying and you'll get it to work. If it still doesn't, relog and make sure to only type the command once.