Ignore the mention, please - it was incorrectly linked when I had pasted in a commit number.

@Hans Goudey (HooglyBoogly) Can you take a look ?

This task should be split up into smaller more specific tasks.

After discussing this in the UI chat channel, I don't think this is a better solution than what we currently have.

Thanks for your Investigations. I found a method to avoid it by just baking the rgb sim to keyframes and then removing the rgb world.

How to reproduce the problem from the attached file?
I opened it, and to bake the rigid body simulation I went to: Scene Properties -> Rigid Body World -> Cache -> Bake. But no crash.
Then I saw that I had to add a turbulence field.
So I opened the file again, added the turbulence field, went to Scene Properties -> Rigid Body World -> Cache -> Bake. But also no crash.
It is too time consuming to track down so I didn't open the other file to test.

Still can't reproduce this. The file just simulates fine for me.

Ok great, thanks for testing! Similar to T84649 the update then fixed this crash too. Cheers!

Yes, after some tests it seems to be fixed :D
Thank you for your work and have a nice day

@Michał Wieczorek (michal1000w) Hi! Was just trying out the file but didn't get a crash so far.

Okay, I am lost. Here is my .blend file when I play it it just crashes... With the newest 2.93 build

Oh, I am dum.... I Forgot to mention that bevor simulating you have to add a turbulence field.
But it still seems to work. Now I don£t understand anything anymore

I cannot reproduce this on the latest alpha on Linux. Could you try the latest alpha or beta from https://builder.blender.org/download/ and see if the problem persists?

Also a bit confused why the Fluid modifier (even when set to None) actually does something to the hair edit.
Will have another look with fresh eyes next week.

I may be close to a solution for mass conservation / volume loss issue. Please let me know if I'm on the right track and if this can be more clear in the tooltips

No the type is set to none so it wont do anything to the hair. You can just let it on but like i said its because the hair is the last modifier and dont has the option enabled use modifier stack..

In T85184#1103652, @Silas Opel (Schamph) wrote:

In T85184#1103647, @Indisponible Anonyme (aplgn) wrote:

In T85184#1103643, @Philipp Oeser (lichtwerk) wrote:

In T85184#1103564, @Silas Opel (Schamph) wrote:

The force field is affecting the groom when hair dynamics are not enabled and when they are they are affected when the timeline plays. Is that by design?

This is the same as T71192: Forcefield impact on hair without hair dynamics checked and T55172: Hair is dynamic even it is disabled.
That is not considered a bug.

Well and what about the fluid modifier that changes the hairstyle, only in edit mode while removed ?

Well thats also not a bug. The modifier is before the particle hair and changes the geometry of the mesh (checking modifier stack in the hair particle setting should prevent that). When you remove it the hair has a different mesh and will change the groom depending on it. Its not as intuitive as it should like the force field changing the hair for no reason..

When its not a bug than this can be closed because thats the reason in this file why its changing and the modifier stack order but thats also not a bug. @Philipp Oeser (lichtwerk)