SelDup being annoying

when I use the SelDup command it freezes my Rhino and Windows says it isnt responding so I have to close it through TM.

My Rhino file is so so laggy at the moment so im wondering what the reason for this is / how to get around it.

I am thinking to just move everything to a new document - what do you guys think?

cheers

Without a file or any information about it, can’t say.

@maxwelljamesbarr please run _SystemInfo and paste the results here.
If you can provide the file that shows this behavior we can take a look at it.