I opened an excel file that contains multiple worksheets. The initial worksheet works fine and has a normal cursor, but when I click on this other worksheet, the cursor changes to an arrow with a page behind it. When I move the cursor off of the actual worksheet to any buttons it changes to a circle with a diagonal line, which prevents me from clicking on anything. I cannot scroll the worksheet and cannot click back to another worksheet. Also if I move the cursor near the worksheet tabs, a little black arrow top pops up, similar to the Tab symbol in Word. What is this cursor and how do I get rid of it?