I'm putting this under general because I know this problem can not have anything to do with Pets. I've played this house after Pets and it was fine. I went into this particular Lot and everywhere that there use to be green grass is now a lovely flashing blue 'grass'. I think the house is a downloaded house which I downloaded early on in my adventures in downloading before I learned about CleanInstall. Now, the only odd thing I've done recently is I went through my Custom Content and deleted (in-game) a bunch of stuff including a bunch of custom 'grasses' (I forgot the proper term). Can that be the problem? It's missing custom grass? I tried using the grass tool over it but nothing happens. Any suggestions?

The flashing blue is because you're missing the terrain files that the house was built with. This is a problem that we've gone over with a fine tooth comb trying to figure out how to solve. Please see this thread for more info: http://www.modthesims2.com/showthread.php?t=142042

Thank you. I've been trying LyricLee's tip of coloring it with the big tool and then using ctrl to remove it all and I haven't had any luck. But I'm going to keep trying.

If you remember where you donwloaded this lot or if you have it somehwere in your computer files re-install it to get the terrains for this particular lot back.If not use the cheat boolprop lotTerrainPaints false while you are in the lot.The flashing will disappear but you won't be able to apply any terrain paints in that lot.

It took a couple of tries of painting and unpainting but I finally got it. Thank you.