This error occurs in this scene:

Perhaps the problem is again in my old video card.

The problem boils down to the fact that, when an oject is assigned Domain Type = Fluid, the "Liquid" checkbox appears selected even if it's not.

A minimal way of reproducing the core error is:

• Default cube: Physics > Fluid > Type: Domain; Domain Type: Liquid
• Observe that [x] Liquid appears as checked
• Observe that, under Particles, there is no "FLIP Particles" system
• Observe that checking [x] Liquid manually doesn't go to an "off" state but stays on a "on" state; it also triggers the creation of a particle system

Thank you @Nicola De Mitri (nicolasap), I will update the description.

Unfortunately I'm not able to fix this myself, like I wanted to.

If it helps, it looks like adding something like

RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_Fluid_flip_parts_update");

to rna prop: "domain_type" would likely fix this (except this is not the right way, and for example it would break Quick Liquid, which instead works correctly right now because it calls for the update directly from Python).

I'd like to point out that this bug has a potentially very high impact on usability!

I'm worried that those who are testing 2.82 are *not* taking advantage of the FLIP particle visualization at all, because it doesn't work out of the box!

I just incorporated the suggestions from the discussion. I hope this fixes the issue.

I've tried it and it seems to work well (both manual and Quick liquid)!

Not sure who should do this, but this must be ported to the 2.82 branch too

(Thanks!)

@Nicola De Mitri (nicolasap) Yes, I accidentally committed this to master first instead of the 2.82 branch. Should be fixed now.