Glaeradaneth The core game gets updates all the time to how it runs. Some are so subtle we would never know other than the errors some players get; others are obvious and advertised, like the addition of DirectX 11 mode. So it doesn't really matter whether you buy the newest packs.
The problem isn't that you're trying to run the game on integrated graphics per se, it's more that you're doing so on a computer that has a dedicated graphics card too. And this has definitely been more of a problem over the last few months, maybe not quite dating back to the implementation of DX11 mode but close. I have lots of other examples where the user had plugged the monitor into the motherboard, and switching it to the GPU fixed their game crashing or not loading issue.
At any rate, if you want to try once more, please post a new dxdiag with the adapter in use. Please also look for new errors in the Reliability Monitor. Hit Windows key-R and enter "perfmon /rel" without quotes, and you'll see a chart of errors and updates with a column for each day. Today is on the right.
Look for an error that happened at exactly the time of your most recent Sims 4 crash. If you find one, double-click it to see more details, then copy that info and paste it into a reply here. If you don't see a new error, check back in an hour or so—the Reliability Monitor doesn't always update right away.
I wouldn't suggest you buy a new adapter if the current one isn't working. Quality adapters are cheap to make, so it's unlikely (possible, but unlikely) that the one you bought is so dysfunctional as to be useless.