The Sims 4 keeps crashing

@EllieBucket  Have you tried a new save in a clean user folder yet?  If not, please do so now:  Move the entire Sims 4 folder out of Documents > Electronic Arts and onto your desktop, and when you launch the game, a clean folder will spawn with no content.  (Your saves and other content will be intact in the folder you moved but temporarily not read by the game.)  Don't add anything to the new folder yet; just start a new save and see whether it crashes.

Otherwise, even though it shouldn't be necessary to specify this, please force Windows to use the Nvidia card with Sims 4 at all times.  Hit Windows key-i, choose System > Display > Graphics settings, click Browse, find TS4_x64.exe, and choose the high-performance option.  Restart your computer before playing.

If that doesn't help, please temporarily set your laptop screen's refresh rate to 60 or 75 Hz, or whatever the lowest option is above 60.  This shouldn't be necessary either, but Sims 4 has had trouble with high refresh rates in the past, and this is a simple test.  The option should also be under System > Display, this time under Advanced display settings.

Please continue to test a new save in the clean user folder for now.  You can start adding back your existing content once the game is stable again.

Thank you for answering! I’ll try that and let you know what happens.

Hi I’ve created a clean save and everything on that seems to be working okay on this one, I haven’t done any of the other things you suggested yet but will do so.

When The Sims loaded up, however, I got a “unrecognised video card” pop up. Not too sure what this means.

Thank you.

@EllieBucket  The "unrecognized video card" message means your graphics card's device ID isn't in the game's database.  It's not a problem as long as you're not seeing any graphical irregularities, which you haven't mentioned.  The message only pops up the first time you launch Sims 4, or the first time after you move the user folder—the data that says you've already seen the message is stored in Options.ini inside that Sims 4 folder.

Anyway, if the new save is running fine, you don't need to try the other steps yet.  Instead, copy one of your existing saves from the old Sims 4 folder to the new one and test that, with no other content present.  Since you're copying rather than moving the save, you don't need to worry about the effects of any missing mods or custom content; the old save will be intact in the old folder while you experiment on the new copy.

Ah okay, thank you!

I’ve done what you said, I tried travelling and have been stuck on a loading screen

I went off and came back on and my game crashed when travelling again. 

@EllieBucket  Is this with your old save or the new one?

This is with my old save copied into the clean folder

@EllieBucket  Please try traveling in your new save, for comparison's sake.  And let me know what lot you traveled to in your main save, and also whether it's a lot you've edited or replaced or still the game's default version.

I travelled in the new save to the same lot and that was fine. In my old save, I travelled to Orchid A Go Go, an edited version by PlumbobKingdom, and it crashed immediately.