unable to invocation?

nervusbreakd0wn

I have tried to use this and I can't do this. No matter what I do I just cant do it and I am just a lvl 21.

lazyjacko72

Make sure your inventory isn't full and you don't have anything in your overload inventory slots.
If that looks ok, try invoking in a non-rest area, then invoke in the rest area, seems to fix it.