Am having this exact same problem today - I had to use the all in one installer on a new PC but cannot load all of my old models as the palette is completely wrong. Unfortunately the solutions provided early have not solved the problem. I have the LDConfig.ldr file in my root C:\Program Files\LDraw (64 Bit) but MLCad doesn't either see it or access it. When I click on it though I do get an error at line 323 message. I opened it in Notepad++ and it seems to be with Metallic colors. I have no idea why but the all in one installer seems to have a corrupt file within. I leave it with persons more capable than I.. Also LPub3D won't have a bar of loading, displays the load image for a second then crashes out. So frustrating..
Update - have just revo uninstalled the AIOI I downloaded today and am attempting a fresh install again using the same file. A question I have is that the LDConfig.ldr file did not install to the root (C:\Program Files\LDraw (64 Bit)) originally and instead I found it installed to the LDView folder. Is this correct? If so how does MLCad find it when I ask it to restore the LDConfig palette? Just really confused as have successfully used MLCad/LDraw for over 10 years happily..
Further update - I have found 3 LDConfig files in the Public Documents LDraw folder (LDCfgalt.ldr, LDConfig.ldr & LDConfig_TLG.ldr). Are these in the correct place? When I browse back to where AIOI installed there are none. And when I open MLCad (extracted to a folder in the same place as the AIOI created) the palette remains wrong and no amount of following this helps:
* Right-Click on a color in the Colorbar
* Click LDConfig as Default in the Color Select 0-31 dialog
* Ok
If it doesn't fix the problem
* Place a part in the window panes
* Click on More in the Colorbar
* Click on Load LDConfig colors
* Confirm Restore LD-Config colors for this file
* OK
Also when I open the MLCAD.exe file it says "MLCad is not (properly) registered for it's file types. Register it now?" to which I click "Yes" and the MLCAD opens, but with the wrong palette. When I close the program and re-open it asks the same question again?
I'm really hoping someone here can help - I've spent so long trying to find the answer..