I'm running into this same issue—I've drawn several "spirals" using the poly line tool, used them to make closed 2D polygons, then extruded those into 3D shapes. Ever since then, drawing a circle gives me the spinning beach ball. It seems like I can draw anything else with no problem—straight lines, rectangles, more spirals, whatever. It's just circles that are causing everything to stop.
Both my OS and Vectorworks say they are up to date:
MacBook Pro OS Mojave 10.14.3
Vectorworks SP2 (build 463397) 64 bit
Any ideas to resolve that issue?