After updating to PL 8.5.0, the presets for the tone curve in the Luma channel no longer work.
Not enough that the Fuji simulations have disappeared, more errors than before.
DxO should finally implement a functioning quality control.
Back to Version 8.3. 
Hmmm. Working fine in the Mac version
I have a Mac and its not working here.
Ah!!! Now I see what you mean. Even though you set the presets and the curve changes, it is the RGB channel that is responding instead of the Luma.
Confirmed bug.
On further testing, the luma channel isnāt responding at all to preset changes
I have created a simple preset and this was working even for the luma channel. only the dxo presets for the luma channel are not working.
Hmmm. Iāll look, after lunch, to see what the preset files contain.
Itās working fine for the Win version.
Yes, you can adjust Luma channel manually but the Luma presets do nothing. Iām on Mac also.
Iāve solved it!!! The system presets are stored in the PL8 app bundleā¦
If you go into one of the system RGB presets, you will get something like thisā¦
Preset = {
Version = "12.0",
IsRAWOnly = false,
LocalizedInfo = {
en = {
DisplayName = "Light Contrast (RGB)",
},
fr = {
DisplayName = "Contraste lƩger (RVB)",
},
ja = {
DisplayName = "å¼±ć³ć³ćć©ć¹ć (RGB)",
},
de = {
DisplayName = "Schwacher Kontrast (RGB)",
},
zh = {
DisplayName = "č½»å¾®åƹęÆåŗ¦ (RGB)",
},
},
Settings = {
Version = "19.5",
Base = {
ToneCurveActive = true,
ToneCurveRedGamma = 1,
ToneCurveRedPoints = {
0,
0,
1,
1,
},
ToneCurveGreenGamma = 1,
ToneCurveGreenPoints = {
0,
0,
1,
1,
},
ToneCurveBlueGamma = 1,
ToneCurveBluePoints = {
0,
0,
1,
1,
},
ToneCurveMasterGamma = 1,
ToneCurveMasterPoints = {
0,
0,
0.255,
0.19499999999999998,
0.625,
0.635,
1,
1,
},
},
},
}
The important thing is the Settings version number, which is 19.5
Now, if you go into one of the Luma presets, you will get something like thisā¦
Preset = {
Version = "12.0",
IsRAWOnly = false,
IsSystem = true,
LocalizedInfo = {
en = {
DisplayName = "Light Contrast (Luma)",
},
fr = {
DisplayName = "Contraste lƩger (Luma)",
},
ja = {
DisplayName = "å¼±ć³ć³ćć©ć¹ć(Luma)",
},
de = {
DisplayName = "Schwacher Kontrast (Luma)",
},
zh = {
DisplayName = "č½»å¾®åƹęÆåŗ¦ (Luma)",
},
},
Settings = {
Version = "19.0",
Base = {
ToneCurveActive = true,
ToneCurveLuminancePoints = {
0,
0,
0.24000000000000002,
0.21499999999999997,
0.74,
0.78,
1,
1,
},
ToneCurveLuminanceGamma = 1,
},
},
}
Note that, in the Luma version, the Settings version number is only 19.0.
If you change this to 19.5, all should be well.
After further inspection, you might like to check the version number on all the system presets. I found some of the RGB also had 19.0. So, I changed them all, just in case.
Thatās curious, Joanna - For the Win version, all āVersionā settings are for 19.0 (not 19.5) ā¦ and Luma presets are working fine.
John
Thank you @Joanna , I have it changed in 3 presets and its working fine.
Curiouser and curiouser.
Well, in that case, I can understand 19.5, as it is PL8.5 plus 11. Maybe because the upgrade is considered significant enough to warrant its own point value - but only on some Mac presets 
And yet PL8.3 only uses 19.0.
Out of curiosity, do all the rest show 19.0 or 19.5?
Very strange, all the presets contains 19.0 ( RGB and Luma)
I change the strong luma preset with 19.5 and itās working !
I get a sneaky feeling that someone forgot to update the resource before the final build. I have changed all of mine to 19.5, for consistency - even though I realise that the next update should overwrite them all, but hopefully with the correct version, whatever that is intended to be.
Whereas, I have just tested and values less than 19.5 (e.g. 19.4) donāt work but any value greater than 19.5 (even 200.0) work just fine. (for the three luma presets)
But, with the RGB presets, I can go down as low as 7.0 and they will still work, but 6.9 shows a totally black image.
Come on DXO, could we have a bit of consistency please?
All presets (in tone curve) have the 19.0 setting, except the luma settings they have the 19.5 now.
Iāve been reading this thread because I have some similar issue since I upgraded PhotoLab 8 to version 8.5.0 build 42.
However, the custom preset that I created is not present at the location that was pointed out in the opening post of this thread. That is, if I interpret the given information correctly.
When I open de DxO PhotoLab 8.app package on my Mac and go to the directory shown in the screenshot, thereās no sign of my custom preset.
The first screenshot below shows the dialog with the preset (under ā0 - Personalā), the second screenshot shows the content of the Presets directory (full path visible at the bottom of the Finder window).
Iāll have to look for the preset using the Terminal app and a Unix/Linux search command to locate the presetā¦
There wonāt be, because that location is inside the PL8 app bundle and contains the Tone Curve presets. Where you are looking is at the folder that contains the āglobalā presets.
To see the folder structure you see in my post, right-click on PL8.app and select āShow package contentsā from the context menu.
For the sake of your sanity, copy the presets folder somewhere safe in case you make a mistake
I did your fix, changing 19.0 for 19.5 on all three Luma curve presets and it seems to work fine. Thanks for the workaround, I would never have found that.
Thanks. Luma Presets working now.
You are confusing the tone curve presets with the edit presets. The tone curve presets are those you choose in the drop down menu of the tone curve tool. You have RGB light, medium and strong, luma light medium and strong, and a few others.
