Just a heads up in case someone else is experiencing a similar issue. This solution is a result of several days of fighting with a Visualize project, manually adjusting scale and X/Y/Z coordinates for dozens of individual parts, and the project finally crashing. Solution was discovered during troubleshooting.
I'm a tech writer using Visualize 2018 and the engineers use 3D 2018. I'm a new user (less than 3 months) but had some basic training from the previous writer.
I opened a 3D 2018 assembly in Visualize 2018 and immediately noticed missing parts and that funny "digital camo" pattern (my term) that I've seen referred to as "Z-fighting" in a different thread. It indicates conflicting parts or duplicate parts, and maybe more conditions that I'm not yet aware of. (yes, that was bad sentence structure!)
The engineer used envelopes in his 3D file, which apparently Visualize interpreted as duplicate parts. Once he suppressed the envelopes in 3D, I was able to open the file in Visualize without conflict. No digital camo, no missing parts. No crashing.
From now on, I will ask the engineers to suppress any envelopes before I bring the file into Visualize.
All feedback and tips welcomed!