Why do I keep getting publishing error?

When I try to publish my page, it says " Publish Error Can't create the file "shapeimage_3.png." The disk may be damaged or full, or you may not have sufficent access privileges." shapeimage_3.png is one of my files, but it appears singled out at complete random. What disk is the error referring to? This has been a problem since I got my new iMac (Yosemite), which is much newer than the old laptop I was publishing from. Any insight is appreciated!