Turn it off. Go out of options. Go back into options and turn it back on. I had a problem where you could pre-select objects and erase etc. It stopped working. I found this one out a while ago! Bit of a pain!!
Here is a diesel string that I use to give the drawing path and name, the layout name, the date plotted and the user name. This is saved as a seperate drawing and inserted as a block into the title block drawing which is then inserted into the layout of a drawing in paperspace. It works brill...
Another way is to open the A3 border file save it to a new file. Scale the entire contents about 0,0 by 1.4 and resave. This should make an A2. The same scaling factor can be used for any Ax to Ax+1 paper size. For Ax to Ax-1 paper sizes use a scaling factor of 0.7. They are not exact, but will...