Just started having this issue. When I specifically try Select Duplicate and Unique Cells based on 6 selected columns (something that I have been able to do for two years), Excel shuts down. When I open Excel, I get a message that states Excel is running into problems with the 'kutools for excel 17.00' add-in. If this keeps happening, disable this add-in and check for available updates. Do you want to disable it now? I did do this when I went from 16.00 to 17.00, but that did not solve the issue. I am using Excel 2013 on the most current version of Windows 10 Pro. Any suggestions?