Insufficient memory crashes, but why?

@Kimmi81  Sims 3-generated crash logs are often useless, and the Crash Log Analyzer isn't much better.  But in this case, both are correct:

Total virtual memory: 4095 Mb
Free virtual memory: 332 Mb

Sims 3 is a 32-bit game, meaning it can't use more than 4 GB memory no matter how much you have installed.  This is a mathematical limit that cannot be overcome.  The actual limit is a bit lower, more like 3.7 GB, because some of the memory is dedicated to overhead, for example translating 32-bit calls to 64-bit for the system to process.

Your save is using too much RAM, and the game is crashing as a result.  Finding the reason can take a bit of investigation, but it's not because of your computer, it's because the save is too complicated.

The next questions are, how much memory is Sims 3 using immediately after you load this save, when the game clock has only run for a few sim-minutes?  What world are you playing in, and how many resident sims does it have?  If you have NRaas MasterController installed, click City Hall and select NRaas > MC > Demographics > Population, and post a screenshot.

@puzzlezaddict After a few sim minutes the game uses 2.136,7MB. Screenshots of the population have been added. The world is a custom world, Great Bear, but adapted (in-game, not in CAW) to serve my needs. And, like I said, I've built big, CC-heavy lots in this world. 

The thing that baffles me the most though, is that I never had any issues with this save on my previous computer, running on the same settings. I would only get insufficient memory crashes if I kept it running for literally hours on end. 

@Kimmi81  Those demographics seem fine, nothing that the game can't handle.  How does RAM use behave as you play?  It would be helpful to know whether you get a steady climb as you play, or sudden spikes, or there's no sign at all that Sims 3 is getting close to the memory limit before the crash.  To test, play in windowed mode and position the relevant value in the Task Manager where you can see it behind the game window, and glance at it every few minutes to see how it behaves.

I would also suggest running an MC town reset (MC > Town Options > Reset Everything) to see whether it helps.  You can exclude the current lot, under MC Settings, if you don't want your own sim reset, and running the reset in the middle of the night should be minimally disruptive.

If that doesn't help, please list the mods you currently have installed.

@puzzlezaddict, Thanks, I will try that and get back to you.
I do have an addition: I noticed a script error file gets created every time I load this save. I pasted the last one to a .txt file and attached it. Don't know if this means anything, but maybe it does.

@Kimmi81  This particular scripterror is a correction log: a report that ErrorTrap is doing its job and nothing to be worried about.  ET will create one or two of these almost every time the game loads; the only times I don't see it is when I've just run an MC town reset and saved and quit immediately afterwards.

The scripterror does point to a potential issue though: most of your NRaas mods are out of date.  I don't know for sure that they're all incompatible with your current patch level because I don't have a resource to check old version numbers, and some of these versions may have been built with patch 1.67/1.69 in mind.  But I would still delete and redownload all your NRaas mods to make sure everything's compatible.

Once you've done that, let me know how the save's memory use behaves.  And please also let me know what speed SP is using, and whether it helps to run it on Snail, under General Options > Adjust Speed.

@puzzlezaddict Ah, thank you! Yes, I've been away from TS3 for 5 years and only came back to it a year ago, so it makes sense some things are outdated... 

Does re-installing NRAAS mods mean I have to redo all settings though...? Dreading that...

@Kimmi81  Updating the mods won't affect their settings, which are stored within the save.  You'd only need to redo the settings if you played without the mods at all and saved your progress.