It's not easy searching for the meaning of error codes, especially negative ones. The best I could find on this was some type of resource error.
-1712 is apparently a "timeout" error, meaning that some program tried to do something, and it couldn't complete the task and so it "timed out". This would likely occur if you are trying to access some external resource that isn't available.
I suggest trying several things in this order.
Quit & restart Pages
Use Disk Utility to repair permissions
Restart your Mac
As Peggy notes, a -1712 error is a timeout error for Apple Events. Often your Mac sends an Apple Event to a program asking it to start (when you double click an icon in the Finder) or to open a document (when you double click a document icon in the Finder).
Can you explain to us what action you're trying that causes this timeout error? And as Peter requests, please tell us the version of Pages you're using.