I have that old fashioned Complete Collection with an applied 4GB patch. I feel like it's even worse with the patch. The game randomly crashes whatever I do short time after opening. The lot size doesn't matter nor what I do. Visiting community lots is a joke. When it crashes it usually shows a screen with flashing green or colorful squares or the usual crashing window or the game freezes where I'm forced to restart my computer.

I had the same CC on the same computer and I usually didn't have problems. I used to make entire overly cluttered lots with barely any issues with the 4GB patch. I have no idea why is this happening. My laptop freezes sometimes and I need to have it checked so I'm not sure if it hates the sims or the sims hates it.

Can you post your computer specs?

Have you set up GraphicRules? Sounds like the game maybe doesn't recognize your graphic card/chip properly, and is having issues running because of this. It will run with the lowest settings and often with graphic issues, freezing, etc. Could also be issues with the display, which is mainly fixed via GraphicRules.

Is the laptop starting to get old? If it's 4-6 years or more, it could be slowly decreasing battery life, dust buildup, overheating parts, or wear&tear if you've moved it around a lot.

Freezing issues both related and unrelated to playing the game can be an indication that something's off either in the software (OS) or hardware (RAM/CPU, etc.), or simply that the computer is working very hard on something and is best left alone for a few minutes. If you have Windows 10, (temporary) freezing issues seem to be part of the OS due to some processes that seem to hog the capacity of the harddrive (for an hour or three if you're unlucky, and freeze the computer if it gets too bad).