Crashes: symbol creation

[Assemblage]

Here's a nasty one: we found creating a symbol whilst in the editing space of an existing symbol sometimes causes all files the file is referenced into to crash. It's taken us a while to figure it out, as the primary file is still open-able and appears normal. Even taking copies of the file and methodically striping out every resource and PIO it's still very difficult to isolate the culprit. We only discovered it by the team discussing their drawing behaviour around the time of the problem as we couldn't figure it out by 'resource deduction'. It's an easy thing to happen if you have some larger symbols which encompass a number of elements on one floor of the building for example. Create symbols in 'clean' drawing space if you can.