Most likely the report (the rpt file) that the user on the Windows 10 machine is using was saved in a format that Crystal Viewer cannot handle.
To resolve, do the following:
1. Check and see if the rpt files are on another machine that has Crystal 11 AND were saved in Crystal 11
2. If so, you can copy those to the Windows 10 workstation.
Important to note:
If you do that, you should not save or edit those rpt files in Crystal 2016 or you will have the issue again on the Windows 10 machine.