selection tool not working at all

I don't know what I accidentally clicked on, but I'm no longer able to use the selection tool in Illustrator CS6.  Other forums mentioned having accidentally hidden the bounding box, but I checked and that wasn't the issue.  I tried to close out the program & re-open it, and that didn't work either.  Instead of an arrow, I get a cross with a small "no" symbol right below it (see example below).  Any suggestions would be most welcome - thanks in advance!