Windows 7 Professional 64-bit.
Using setup_supreme_commander_2_1.260_(38746).exe installer.

Can't launch the game at all.

I also notice that the folder ".\Supreme Commander 2\bin" has a "steam_appid.txt" file.

Have you tried WinXP Compatibility mode?

Yes, no change.

Did you check the Event Viewer?

2 application errors.

Error 1:
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Windows cannot access the file for one of the following reasons: there is a problem with the network connection, the disk that the file is stored on, or the storage drivers installed on this computer; or the disk is missing. Windows closed the program Supreme Commander 2 Application because of this error.

Program: Supreme Commander 2 Application
File:

The error value is listed in the Additional Data section.
User Action
1. Open the file again. This situation might be a temporary problem that corrects itself when the program runs again.
2. If the file still cannot be accessed and
- It is on the network, your network administrator should verify that there is not a problem with the network and that the server can be contacted.
- It is on a removable disk, for example, a floppy disk or CD-ROM, verify that the disk is fully inserted into the computer.
3. Check and repair the file system by running CHKDSK. To run CHKDSK, click Start, click Run, type CMD, and then click OK. At the command prompt, type CHKDSK /F, and then press ENTER.
4. If the problem persists, restore the file from a backup copy.
5. Determine whether other files on the same disk can be opened. If not, the disk might be damaged. If it is a hard disk, contact your administrator or computer hardware vendor for further assistance.

Additional Data
Error value: 00000000
Disk type: 0
---

Error 2:
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Faulting application name: SupremeCommander2.exe, version: 0.0.0.0, time stamp: 0x4f46f777
Faulting module name: common.dll, version: 0.0.0.0, time stamp: 0x5eb015d3
Exception code: 0xc000001d
Fault offset: 0x0001b979
Faulting process id: 0x19b4
Faulting application start time: 0x01d63ee0150daf0c
Faulting application path: C:\GOG Games\Supreme Commander 2\bin\SupremeCommander2.exe
Faulting module path: C:\GOG Games\Supreme Commander 2\bin\common.dll
Report Id: 55903d4c-aad3-11ea-8f17-7085c2494671
---

Comparing the GOG version to the Steam version only the GOG has common.dll in that location. I am able to run the Steam version without issue.

I face a Supreme Commander 2 launching issue too. Where did you get your errors logs from so that I can see if I have the exact same problemm?

Control Panel > Administrative Tools > Event Viewer > Windows Logs > Application

Nothing appears in there. I tried to open the game with event viewer opened, the game icon appears for less than a second in the task-bar, the screen flashes as if the splash-screen was displayed for a few frames, and then ... nothing. Not even a new log event in the viewer :/

Also, an interesting point to note is the game was launching successfully yesterday, before Windows Update installed a few patches...

That's more than it does for me.

I have all updated for Win10 1910. No problems for me.

Same problem. Game not start at all.

Not sure if this helps, but Since I don't use gog galaxy, I use the offline version, for it to install and play right, I have to unblock the exe, and all parts of the game, right click properties, unblock, apply.

What do you mean with "unblock"?

I installed from offline exe (downloaded from "bonus" section in GOG galaxy 2.0), tried to uncheck readonly on game folder (and apply to all subfolders) but game still doesn't start.