Are you sure you are on the Mask and not the Layer? Are any of the locks on the Layers Palette active?
What version are you using? What does the message say?
Message: Could not complete your request because the target layer is hidden.
CS3
The only lock is on the background layer.
I clicked on the mask. The mask has 2 solid borders areound it.
Sounds to me like you are trying to do something to a Layer (Or the Mask on it) which has the visibility turned off.
Hmm… maybe not visibility but the object could be a sub-object which is locked with in an unlocked layer.
Check your layers pallette and expand all of the layers. Look for locked sub-layers and click on the little padlock to unlock it.
My apologies if you’ve tried that, just grasping at straws here
My apologies… my brain was in the Illustrator forum and my computer was in the Photosop forum. So that may not be a correct answer. However, your object still could be on a locked layer. Check for little padlocks anyway.
Figured it out. Thanks for all the help.
Ivan