A lot more information about your hardware and software is needed.
If you give complete and detailed information about your setup and the issue at hand,
such as your platform (Mac or Win),
exact versions of your OS, of Photoshop (not just "CC", but something like CC2014.v.2.2) and of Bridge,
your settings in Photoshop > Preference > Performance
the type of file you were working on,
machine specs, such as total installed RAM, scratch file HDs, total available HD space, video card specs, including total VRAM installed,
what troubleshooting steps you have taken so far,
what error message(s) you receive,
if having issues opening raw files also the exact camera make and model that generated them,
if you're having printing issues, indicate the exact make and model of your printer, paper size, image dimensions in pixels (so many pixels wide by so many pixels high). if going through a RIP, specify that too.
a screen shot of your settings or of the image could be very helpful too,
someone may be able to help you (not necessarily this poster, who is not a Windows user).
Please read this FAQ for advice on how to ask your questions correctly for quicker and better answers:
Hold down the shift key...
Jeff, the shift key constrains the crop to a square, not to the image proportions...
station_two, I'm not having problems with my hardware or software. I am asking what this tunction does.
If you mean "Constrain to Image", it limits the cropped area to within the image boundaries. So, if you have rotated and/or transformed the image, revealing blank canvas at the edges, your crop cannot include this canvas.
IIRC, this setting is default. You might want to switch it off if you need more of the warped image in Photoshop, cloning over the blank canvas which was included in the conversion.
If you don't mean this, then you'll need to explain better.
Yes, I meant "Constrain to Image", sorry.
And thank you for the explanation. Apparently this works different than in Photoshop.