Greg -

sometimes a distribution updates a library to an incompatible new version, in which case the version number attached to the file name changes. This could have happened here and would require CMTK to be rebuilt using the new system library versions.

That said, John, I forgot to ask the most basic question first - did this ever work on your system, then stopped, or is this a new system which hasn't had Fiji/CMTK working before?

If it's a new system, the problem could also be that you simply don't have the DCMTK library installed. Since apparently (guess I should know that by know) Fiji is distributed outside the package system, there's no safeguard against missing dependencies.

I am not sure what the exact command is to install DCMTK on Ubuntu, but something like "sudo apt-get install dcmtk" might work.

Best,
  Torsten