Ok, If you cant do the disable esl stuff yet, lets start at he basics. Sort of.
Is your sanctuary build a city plan or your own.
Do you have extra stuff you have done in Abernathy farm and or Red Rocket?
When it crashes, do you see by any chance a message that says something like xxxx is upgrading there home / factory / shop? (This may be a bit pie in the sky, coz unless you are looking for it, its easy to miss) If this is the case, then there is a plot causing the issue as it upgrades.
If, its a custom build, do you have lots of plots? I have a city plan there and a custom build at Red Rocket, with no "real" issues. I do have to be careful as I approach RR as it CTDs often. So I always make a sneak approach.
Do you have Fallrim Tools? This is a good way to check to see if your save is "busted" or has issues.
@RayBo has done a really good tutorial / video about this. It is well worth the watch, even though you may feel a bit intimidated by it. (Only say that coz you said you now nothing about modding).
Link below takes you to a
@RayBo's page that goes over many of the fixes / checks you can do to check your save etc.
https://www.simsettlements.com/site/index.php?threads/bags_2-0-bake-a-game-save.11773/#post-81186