Thanks for the info Rose
In the two new saves I started, I was able to place Chez Llama, a game spa and a gallery house on the lot next to Comfy Cozy and was able to put one of deannacarver's parks in Newcrest and place a household from Simslover163 in the house to help populate the world a little. Then went I went into another lot to add the next build it wouldn't even load and was given an error and notice to restart the game. I don't think there were Sim paintings in the builds.
When beginning a new game save, I like to add one venue lot in each of Newcrest's sections along with two house builds either from the regular, friends or my gallery and then have one of the houses occupied. I leave the other builds for townies to move in. In each game save I tried, it seemed to be a different lot that started the issue. Even repairing the game didn't work. I don't use any CC or mods.
Guess, it's not meant to create extra game saves for now. If my husband gets the new laptop working right, I may try again but will probably start everything fresh. Could try to build up Newcrest over time, as well.