If you suspect the issue is a mod conflict but you can't work out what's causing it, you can share your modlist with me here and I'll look into it for you. To do this:
https://i.imgur.com/QZOcy71.png
Select the 2 circled buttons in the launcher, click "copy to clipboard", then paste it somewhere such as https://pastebin.com/ and then copy and paste the link here.

If I ask for a save file, they can be found at "Documents\Paradox Interactive\Stellaris\save games" - upload the latest .sav file in the specific save folder and pop it on https://filebin.net, then put the resulting link here. Thank you!

Ok, you might be right, here is my list > https://pastebin.com/ZR7eKuZj
The tooltip with civilian vessels says "+1 disengagement opportunities" instead of the one from your mod. Combat ships are not overwritten though...

https://pastebin.com/T4v2HhR2

sorry it took me so long, I apologize for the long modlist too. ALSO, if you see that your mod was disabled on this list, that was after the fact

Originally posted by TurgidJuiceTree:

https://pastebin.com/T4v2HhR2

sorry it took me so long, I apologize for the long modlist too. ALSO, if you see that your mod was disabled on this list, that was after the fact

Thanks for the list, and no need to apologise for any of that! The only incompatibility I see on there is Ancient Empires, which is something I can't fix currently, only wait for the mod author to get in touch.
Does the issue still occur (in a fresh save) with AE disabled?

Day 5 crash of a new game, repeated multiple times, but not guaranteed. So far the crash rate is 75%. Let me know if the Paste expired, it's set to burn after access.
EDIT: Ok, some rando definitely just burned it. Welp, lesson learned. NEW LINK!
https://pastebin.com/DuVHS1x8

Originally posted by Gake:

EDIT: Ok, some rando definitely just burned it. Welp, lesson learned. NEW LINK!

Pff that was me actually, I was on it in a flash.
I've been unable to replicate the crash so far - does disabling only my mod in the list prevent the crash ever happening? Are you using a modded origin/game changing civic when this crash happens?

Could you also please check if this crash still happens when you disable "Guilli's Planet Modifiers and Features"?

I'll have to take a better look at it tomorrow if so, it's hard to work out why it might be happening though cause this mod doesn't do anything specifically 5 days into a save.

Originally posted by Jaysus273:

Originally posted by Gake:

EDIT: Ok, some rando definitely just burned it. Welp, lesson learned. NEW LINK!

Pff that was me actually, I was on it in a flash.
I've been unable to replicate the crash so far - does disabling only my mod in the list prevent the crash ever happening? Are you using a modded origin/game changing civic when this crash happens?

Could you also please check if this crash still happens when you disable "Guilli's Planet Modifiers and Features"?

I'll have to take a better look at it tomorrow if so, it's hard to work out why it might be happening though cause this mod doesn't do anything specifically 5 days into a save.

I've narrowed it down to Gigastructures, Guilli's Planet Modifiers and Features, and this mod. Disabling one of the three stops this crash from happening, but the crash rate has dropped to ~20% of the time.

EDIT: Okay! I have good news! I was able to definitively rule out THIS MOD as being the culprit. Sorry for the false alarm... It's Gigastructures + Guilli having incompatibilities.

Originally posted by Gake:

Originally posted by Jaysus273:

Pff that was me actually, I was on it in a flash.
I've been unable to replicate the crash so far - does disabling only my mod in the list prevent the crash ever happening? Are you using a modded origin/game changing civic when this crash happens?

Could you also please check if this crash still happens when you disable "Guilli's Planet Modifiers and Features"?

I'll have to take a better look at it tomorrow if so, it's hard to work out why it might be happening though cause this mod doesn't do anything specifically 5 days into a save.

I've narrowed it down to Gigastructures, Guilli's Planet Modifiers and Features, and this mod. Disabling one of the three stops this crash from happening, but the crash rate has dropped to ~20% of the time.

EDIT: Okay! I have good news! I was able to definitively rule out THIS MOD as being the culprit. Sorry for the false alarm... It's Gigastructures + Guilli having incompatibilities.

I think it might simply be a case of the initial generation events in the first few days overloading your system - it'd make sense if your crash rate varies, as system usage can vary throughout the day. I meant to say this earlier, and specifically mention Giga and Guilli's as the two major offenders for that, but I forgot.

I'm glad it wasn't this causing the issue, cause it would've been a huge pain to work out why. But yeah, until Paradox improves 4.0 performance I guess I'd recommend closing as many programs as possible and pausing every day for the first 5-10 days of a game, whenever you start a new game.