Canon Navigator EX no longer running after High Sierra

I have a Canon Pixma MP990 that I now use only as a scanner. I have been using the Navigator EX 3.0 software supply by Canon. But after updating to High Sierra, this no longer works. (Here is part of the error report generated when it crashes when I try to open it:

Application Specific Information:

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSImage setNumOfRow:]: unrecognized selector sent to instance 0xfb2c870')

I have tried downloading more recent versions of the software provided by Canon, but none of them work with the MP990.

Any suggestions as to what to do to get this to work? It was a good scanner interface.

Thanks in advance for your help.

Kent