Game Crash Too much decor? Too many attractions?

[fountain]

After the zoo loss disaster a few weeks ago I found a very early (only 6 - 8 exhibits, gifts, food) copy of that zoo.  I dried my tears and redesigned, rebuilt my contest entry to 30 exhibits.  I used many, many, coral decor in water areas and many shells, sea stars, etc.

    While on pause year 5?, I dismantled an exhibit I didn't like, "filled in" its wetland, unpaused to allow maintenance to clean leftover animal food, paused again then placed a second zoo aviary with the Tropical Birds selection, changed roof color. The first aviary (dozens of sq away) I switched from Tropical Birds to Birds of Africa. I may have placed a rainforest pond beside that #2 aviary.  I placed a primate house 8? sq away from aviary #2.  Chose middle animal option, test roof colors-- game crash.

     Fortunately, I saved before testing roof colors so restarting the game no problem. Except game crashed almost immediately.

     Years ago similar timing, almost immediate crash, was because I was using developer tools and accidentally put sea urchin into a tank as a developer. Removed sea urchin while in developer menu, problem solved -- after a couple days. Fern and Jay got me through that. 

     But Beach Contest only standard in game topographic changes are made, no map editor; no sneaky sea urchins (or feral children ). (Old joke.)

 

Where I do start to figure this out?      Thanks in advance.