@agutz Certainly.

Under Windows 10 settings, go to Language (you can also press Start->Type "Language Settings". 

Then, on the right, you'll find a link that says "Administrative language settings".

If you click on that, the second group box is "Language for non-Unicode programs". I changed that 'system locale' to English (United States). 

@SkyyStorm, thanks for the explanation.
I don't have this problem opening .PLN files in LNV.
My current language for non-Unicode programs (system locale) is English (US).

So my problem with RC4 in W10 persists.

Ah, that's unfortunate. 

The only other thing that has a possibility is some application that is interacting with the RC exe, like a debugger (see a few replies of mine back where I mentioned that the debugger creates the same behavior on a pc where RC works).

Perhaps you have something that is debugging, or something like an anti-malware/virus program that is running in the background. But if my previous comments didn't help you, I'm afraid I don't have the answer for you good sir.

@agutz, Install NotePad++ and use it to open a P3D flight plan.

Down in the status bar it shows the encoding used by default. Make sure it uses UTF-8 character set.

Just to confirm you are also having the problem of the RC4 splash screen not showing and the program just terminating with nothing recorded in Event Viewer.

@Ray, I have Notepad++. The .FPL is encoded in UTF-8-BOM. Little Navmap and all the others can read it
And, yes, I confirm I'm also having the problem of the RC4 splash screen not showing and the program just terminating with nothing recorded in Event Viewer. In the EV I checked Windows Logs - Application. Should I also look elsewhere?

Thank you, Ray, for still showing interest in this weird problem which seems to be extremely rare and specific to few setups of W10.
When I use another old W10/32bit PC as client on a network I can run RC4 there and connect (WideClient) to the server PC.

Right now, however, I am using P3Dv4 in a W7 setup. I will eventually repair/reinstall (whatever it takes) this particular W10 partition. Presently  I'm visiting it only in the context of the "RC4 enigma".

Hi Andreas,

UTF-8-BOM is fine so we can discount that as the cause. Judging from SkyyStorm's replies the answer may reside in language settings but you have already checked that and it seems okay.

In Event Viewer I view it at Overview and Summary - Summary of Administrative Events. There are main entries such as Critical, Error, Warning etc.

The one you should check is Error. Open that up and check Application Error for any entries. I would have expected to see an entry there if a program was launched but then immediately crashed.

As your other W10 PC is 32-bit we can't easily compare systems. It's probably a setting but which one is the mystery.

Edited March 28, 20197 yr by Ray Proudfoot

Hi Ray,
mystery, indeed!

No, there are only a few recent app-model runtime errors referring to Skype/YourPhone/Ms WindowsStore. (I used none of them).
To me it looks like RC4 doesn't crash, it doesn't get launched at all!
BTW: RC4 is listed in "Programs and Features".

Hi Andreas, I’m sorry but I can’t think of what could be causing it unless it was a language problem similar to SkyyStorm’s.

I paid a Microsoft Certified Engineer to identify a USB problem I had on my PC in January. Turned out to be an incompatible powered USB hub with W10.

It might be worth you investigating that option.