We were not able to reproduce the problem. We tested the program with 70Mpixel at 16 bit images ( 420 Mb tiffs) and everything is fine. Can you upload one or two of your files (as described at http://www.heliconsoft.com/ftp.html
)? Another reason that can cause such a message is the date inside of the file. If the file is dated in the future, the program will not open it.