When I add dimensions in annotations mode in Viewport, it crashes (or massively slows) my programme. I use VW2019 SP2.
Any advice? - is this unusual??
It can be, if you are able to alleviate it by doing the very strange troubleshooting step of undocking your Object Info palette and leaving it simply undocked, then this is a known bug that will be corrected in 2019 SP3. I believe however that there are other steps support will want to perform on that machine as well.