Thank you, Dan (and thanks for replying so promptly). I've uploaded one of the 30D files to your FTP site. The file name is IMG_7525.CR2.

The file opens fine on my other computer that also runs Helicon Focus 4.16, by the way. So it will seem odd if it turns out to be a problem with the file.

I ...

I'm running Helicon Focus Pro 4.16 on two computers. On one of the computers, I have been running Helicon Focus Pro successfully for several months, and it works fine with files from both my Canon EOS 20D and my EOS 30D.

However, I installed Helicon Focus on the other computer today, and it does ...