some aircraft models would show black squares of smoke momentarily on touchdown which rapidly disappears, then the white smokes appear as normal (as shown below)

this doesn't happen when I turn off DX10, but also doesn't happen on all aircraft models although DX10 was enabled

 

 

A lot of aircraft are not DX10 compatible!  Maybe try the payware "Steve's DX10 Fixer".

15 minutes ago, charliearon said:

A lot of aircraft are not DX10 compatible!  Maybe try the payware "Steve's DX10 Fixer".

I tried it already, but the problem remains

 

Do all of the aircraft use the same touchdown effect in the aircraft.cfg?  Example shown below.

Possible corrupted effect?

[EFFECTS]
wake=fx_wake
water=fx_spray
dirt=fx_tchdrt
concrete=fx_sparks
touchdown=fx_tchdwn_s, 1<--------------

the .cfg file for the aircraft with black smoke is

[EFFECTS]
wake=fx_wake
water=fx_spray
dirt=fx_tchdrt
concrete=fx_sparks
touchdown=fx_tchdwn, 1
vaportrail_l=fx_dummy
vaportrail_r=fx_dummy
EngineFire=cs757_smoke_dark

 

Another .cfg for normal one is :

[EFFECTS]
wake=fx_wake
water=fx_spray
dirt=fx_tchdrt
concrete=fx_sparks
touchdown=fx_tchdwn, 1

On the one aircraft with the black smoke, try this edit to see if it corrects the problem.  If the problem

is corrected then eliminate the slashes one set at a time to find the culprit.

[EFFECTS]
wake=fx_wake
water=fx_spray
dirt=fx_tchdrt
concrete=fx_sparks
touchdown=fx_tchdwn, 1
//vaportrail_l=fx_dummy
//vaportrail_r=fx_dummy
//EngineFire=cs757_smoke_dark

adding slashes didn't resolve the problem

I tried adding (_s) to the touchdown line as you mentioned above, to be like that :

touchdown=fx_tchdwn_s, 1

The black smoke disappeared !, but the white smoke "the normal cool effect" has gone too !

The example I gave was from a 3rd party F-9f Panther.  Look through your main Effects folder for any other touchdown reffects you can try.

Any other effects will start out fx_tchdwn......

The only other suggestion is to not use DX10.

I found these 2 files in effects folder

fx_tchdwn.fx

fx_tchdwn_s.fx

In Steve's DX10 Fixer, Lights/Effects tab, convert effects, do you have selected all effects? In that case select all but particles effects.

I ran the setup DVDs twice for repair yet the problem is the same

Also I tried every combination in Steve's DX10 lights/effects box , checing and unchecking all options didn't work it out.

Also noticed black squares of rain drops as below, I don't know whetherboth problems are related or not

What's next?  Black contrails?  Better check!

Contrails and wingtip vortices are white

touchdown smoke is also normally white (It only starts as black squares then normalizes to white)