I'm at my wits end with this. One day I loaded up the game to see that the thumbnail for Desiderata Valley was a green grid (see image) and I have tried everything I can think of. I have uninstalled, reinstalled, reset the game, used different neighbourhood templates, but nothing seems to change it back to how it was. Is there anyone who has experienced this, or someone who can help me? I saw a post from a few years ago with a similar problem but I couldn't figure out how they fixed it.

You are probably missing the png, the neighborhood folder. Each hood folder will have it's respective Hood.package and Hood.png (along with other folders). Is this a custom/clean version? If so find the download again, and the png should be in there.

First of all, if the image actually there in your Documents folder? It should be: Users\[username]\Documents\EA Games\The Sims 2\Neighborhoods\F001_Neighborhood.png.

Firstly, thanks for the replies. To answer both of you the .png file is there, as well as everything else that the other hoods have. I've tried reinstalling, resetting the game, using any clean template I can find and it's still like this. There must be something I'm missing?

Do you have an .reia file in that folder too? Where is your Documents folder located- if it's on One Drive then make sure it's not being synched whilst you play, and also make sure your antivirus program has your Sims files excluded from scanning.

I have the .reia file in there, too. As for my Documents folder - it's in OneDrive, but I've unlinked it since. Now whenever I search for EA Games, there's two folders that show up. I've tried replacing both of the Neighbourhoods with clean templates and nothing happens sadly.

Update! I found the fix! There was an old copy of the neighbourhood interfering in C:\Users\<YourUsername>\AppData\Local\VirtualStore and I replaced it with a fresh one. If anyone else gets this problem, I hope this helps!

Good call- well done for fixing it!