So, I did a bit more experimenting with this and i have some new developments.
First, this issue is actually exclusive to Newcrest. I hopped over to Willow Creek today and I was able to switch both a Generic and an empty Residential lot to a Community Space and switch between the tabs.
Additionally, whatever is going on with Newcrest is not actually limited to the community space lots. At first, I thought the problem might have been switching from residential to Community Space (hence why I tried this in Willow Creek later), so I tried switching the lot that's been crashing to Generic first. The game crashed when I tried to go back to Manage Worlds after making the change. I then tried a different lot in Newcrest-same thing. So, even if I wanted to turn those lots into parks or restaurants right now, I couldn't. They're stuck being residential.
Later on, I want to try placing a community space lot from the gallery directly from manage worlds and switching the lot type from there. It's worth a shot.
