Hey Timmy. I initially had a problem with my SD card on my Creator Pro. I chalked it up to running everything on my Mac and possible compatibility issues. Then I did some research. I found another post on here that says that the file names on the card have to be within a certain limit and cannot exceed that character length. I also found that the printer can only read one or two SD card formats, FAT16 or FAT32. Since I found this information and after some experimentation I have been able to successfully use the included SD card as well as two other SD cards for printing and file transfer via ReplicatorG.

In a nutshell:

1. Keep your printing file names short, as short as possible while still being able to recall what that file is.
2. Check to ensure that your SD card is in FAT16 or FAT 32 format
3. Dummy check to ensure that the read/write switch on the side of the SD card is NOT in the lock position.
4. If you are running OSX on your computer I recommend running a Virtual machine with windows so that you can get the correct format for the SD card.

Let me know if that helps.