Although there is no technical limit to the size of image file to be imported, smaller files often work better. Therefore often the best way to get round this problem is to simply reduce the size of the image file.

• JPEG's come in many different formats, and though there are standards, some programs have problems with certain JPEG's
• BMP's , GIF's or even TIF's use a simpler compression technique and are therfore easier to import.
• Out of those files the best for this program is the TIF files. Also using a RGB colour scheme tends to work the best.
  Try using a photo editing suite to change the colour and file type to the ones above and it should work no problem.

You can get more info on how to do this at this link