spqsu88wmni0 I'm sorry, but that guide you've linked has a LOT of "essential" steps that are not essential by any meaning of the word, and at least one that's incompatible with NRaas mods. (I stopped reading after the third or fourth "essential" step in a row that doesn't even qualify as "highly recommended.") Sims 3 doesn't need nearly this much work to get running, and in fact doing all these steps can break the game.
Additionally, it's crucial with an older game like this to only add or change one major feature at a time. Sims 3 wasn't built for modern hardware, and although it usually runs fine, adding a bunch of (also unsupported) extra variables at once is asking for trouble. Further it makes fixing problems much harder because of all those extra variables—you don't know if a problem is coming from your system or one of these add-ons or the game reacting to the add-on or two of them conflicting with each other, etc.
Point is, please delete all the files you added, mods or otherwise, and repair the game. If you have an EA App install, the option is Sims 3 > Manage > Repair; in Steam, it's Sims 3 > Properties > Installed Files > Verify integrity of game files. The idea here is to return to a vanilla state, fix the shadow issue, and only then add one thing at a time.
For reference, please also provide a dxdiag. Click Windows key-R, enter dxdiag in the run box, wait for the scan to finish, click "Save all information," and save the file to your desktop. From there, you can attach it to a reply using the paper clip (Attachment) icon included with the other formatting buttons.
