Why would the extrude always crash ?
If I sketch a separate shape it works no problem …
This has lag and doesn’t work the same ?
Any help most welcome 
Carl
Hi Carl,
Could you please export the file into SHAPR format and send it to us so we can have a look at it?
support@shapr3d.com
Regards,
Peter
Hi Peter
Sent a file thanks
Carl
Thanks Carl, we’ll look into it.
Peter