File Type not recognised?

[cliffyk]

Nothing so nefarious, Chitu updated the compression algorithm for the .ctb format to make smaller files, faster. older printer firmware cannot decompress the new files--however the new firmware can read the old.ctb format with no problems.

Also, Chitu does not control[s] the software/firmware side of things for several 3d printer manufacturers, those manufacturers choose to outsource their electronics to Chitu.