i recently bought Demonicon on Gog after purchasing it on Steam and seeing it how it won't lauch no matter what I do so after thinking about all the old games I bought here on GOG I would have no problem running it here, wrong, the same problem was in the GOG version of the game.

Does anyone know a way to fix it?

What OS are you running?

I'm on Win10 and the game installs and runs flawless.

One caveat, though:
I'm using the older version (1.1_(45947)), not the latest "GOG Game Preservation update" (1.1_(45946)).

You can find the game's log files on %APPDATA%\Roaming\Kalypso Media\demonicon\logs\.

I'm on Windows 11

I have the log but I can't understand any of it

I'm on Win 11 too & the game runs no matter which version.

In my log file there are these lines: Is PhysX started? Is the resolution correct? Or is there at the end of the log some line pointing into a direction why the app refuses to run?

LogThread started. (LogThread|LogThread::Run|..\..\src\utils\logging.cpp|199) time:0.000000 (23:10:12.57)
DATE: Tue Dec 24 23:10:12 2024
(MainThread|logInit|..\..\src\utils\logging.cpp|385) time:0.000000 (23:10:12.57)
log system initialized (MainThread|logInit|..\..\src\utils\logging.cpp|387) time:0.000000 (23:10:12.57)
build type: MASTER (MainThread|logInit|..\..\src\utils\logging.cpp|393) time:0.000000 (23:10:12.57)
ApokalypsoPlugin:OnInitEnginePlugin() (MainThread|ApokalypsoPlugin::OnInitEnginePlugin|src\apokalypso_plugin.cpp|204) time:0.000000 (23:10:12.181)
Using loaded Engine Plugin: 'C:\Program Files (x86)\GOG Galaxy\Games\Demonicon\demonicon_engine_plugin.vPlugin'.
Loading Engine Plugin 'C:\Program Files (x86)\GOG Galaxy\Games\Demonicon\demonicon_engine_plugin.vPlugin'.
Plugin 'C:\Program Files (x86)\GOG Galaxy\Games\Demonicon\demonicon_engine_plugin.vPlugin' loaded
InitEnginePlugin:DemoniconEnginePlugin dynamically from 'C:\Program Files (x86)\GOG Galaxy\Games\Demonicon\demonicon_engine_plugin.vPlugin'
DemoniconEnginePlugin:OnInitEnginePlugin() (MainThread|DemoniconEnginePlugin_cl::OnInitEnginePlugin|src\DemoniconEnginePlugin.cpp|357) time:0.000000 (23:10:12.182)
Launcher good, return code: 128

-->HashManager uses 0.000000 kb to store 0 strings. (MainThread|HashManager::printMemoryUsage|J:\build_server\projects\demonicon_compile_main\executable\include\u tils/hash_manager.h|89) time:0.000000 (23:10:12.215)
Setting Focus to :ea0cb1eb ('"ea0cb1eb" (Hashmanager inactive)') (MainThread|GameState::receiveFocus|..\..\demonicon_source\game_states\game_state.cpp|54) time:0.000000 (23:10:12.215)
DemoniconMusicManager::gameStateChange(unsigned int, bool) "ea0cb1eb" (Hashmanager inactive) false "0" (Hashmanager inactive) (MainThread|DemoniconMusicManager::gameStateChange|..\..\src\sound\demonicon_music.cpp|199) time:0.000000 (23:10:12.215)
Load ValueLibrary. (MainThread|ValueLibrary::ValueLibrary|..\..\src\roleplay\value_library.cpp|41) time:0.000000 (23:10:12.217)
Finished loading ValueLibrary. (MainThread|ValueLibrary::ValueLibrary|..\..\src\roleplay\value_library.cpp|47) time:0.000000 (23:10:12.231)
FX_ENABLE_LOGGING is 1. (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.250)
FX_ENABLE_LOGGING_AUTO_TABS is 1. (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.250)
FX_ENABLE_AUTO_DEBUG_LOGGING is 1. (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.250)
FX_MAX_LOGGING_LEVEL is Logging::Verbose. (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.250)
FX_LITTLE_ENDIAN is defined. (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.250)
Starting up FaceFX SDK... (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.250)
Starting up memory manager... (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.250)
FX_TRACK_MEMORY_STATS is 0. (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.250)
FX_ENABLE_SHORT_STRING_OPTIMIZATION is 1. (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.250)
The allocation type is set to MAT_Custom. (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.250)
userAllocate: 01394D00 (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.250)
userAllocateDebug: 01394D70 (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.250)
userFree: 01394DE0 (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.250)
Memory pooling disabled. (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.250)
Memory manager startup complete. (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.250)
version: 2012.1 (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.251)
build_id: 2121101265 (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.251)
licensee: Noumena Studios GmbH (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.251)
project: Demonicon (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.251)
licensee version: 1000 (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.251)
file format version: 10 (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.251)
Starting up class manager... (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.251)
Class manager startup complete. (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.251)
Starting up name manager... (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.251)
FX_ALLOW_SPACES_IN_NAMES is 1. (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.251)
FX_MAX_NAME_LENGTH is 512. (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.251)
Name manager startup complete. (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.251)
Starting up archive manager... (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.251)
Archive manager startup complete. (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.251)
FaceFX SDK startup complete. (MainThread|FxLogAdapter::MessageLogged|..\..\src\components\facefx.cpp|96) time:0.000000 (23:10:12.251)
Vertical synchronization is enabled. (MainThread|VideoSettings::engineSetup|..\..\src\core\video_settings.cpp|292) time:0.000000 (23:10:12.323)
WARNING: can't set fmod volumes because VFmodManager isn't initialized yet (MainThread|AudioSettings::applySettings|..\..\src\core\game_settings.cpp|59) time:0.000000 (23:10:12.323)
WARNING: OptionsManager could not apply settings! (MainThread|OptionsManager::init|..\..\src\core\options_manager.cpp|87) time:0.000000 (23:10:12.323)
Language selection: found available language 'en' (MainThread|Languages::getAvailableLanguages|..\..\src\core\languages.cpp|160) time:0.000000 (23:10:12.324)
Language selection: GetUserDefaultUILanguage says 'it', but language isn't available. (MainThread|Languages::determineLanguage|..\..\src\core\languages.cpp|64) time:0.000000 (23:10:12.324)
Language selection: Steam says 'en' (MainThread|Languages::determineLanguage|..\..\src\core\languages.cpp|122) time:0.000000 (23:10:12.324)
Language selection: language is 'en' (MainThread|Languages::determineLanguage|..\..\src\core\languages.cpp|138) time:0.000000 (23:10:12.324)
Language selection: fallback language is 'en' (MainThread|Languages::determineLanguage|..\..\src\core\languages.cpp|139) time:0.000000 (23:10:12.324)
Initializing engine
Vision DLL path: C:\Program Files (x86)\GOG Galaxy\Games\Demonicon\Vision100.dll
Vision version WIN32 DIRECTX9 - 2012, 1, 2, 0
Using fast timer
Initializing Vision Graphics Engine
Detecting CPU type and features
Settings renderer configuration
PhysX initialized
Initializing remote debugger
FMOD: created FSB resource: sounds/combat (07FEF3F8)
FMOD: created FSB resource: sounds/all_for_debug (07FEF878)
WARNING: file sounds\pc\all_for_debug.fsb not found (MainThread|VfsManager::Open|..\..\src\core\vfs_manager.cpp|283) time:2.091347 (23:10:14.417)
FMOD: created FSB resource: sounds/global_effects (07FEF578)
FMOD: created FSB resource: sounds/footsteps (07FEF218)
FMOD: created FSB resource: sounds/ui (07FEF758)
Loading Event Manager 1a)
start tree building
finished tree building
start initilizing effect tamplates
stop adding effect templates
Initialising video driver: 0
Setting screen mode to x:1920 / y:1080 / frontbuffer bpp:32 / refresh:0
Screen Mode is fullscreen
WARNING: Could not set screen mode (error:-2).
WARNING: Unable to initialize video mode
Could not set screen mode (error:-2).
VisMain_cl::DeInit
DeInitializing Object Data...
DeInitializing Surface and Texture Data...
WARNING: Resource survived UnLoadWorld : lua\gameplay_base.lua (Scripts), #1
WARNING: Resource survived UnLoadWorld : lua\init_lua.lua (Scripts), #1
WARNING: Resource survived UnLoadWorld : lua/effect_support/effect_definitions.lua (Scripts), #1
WARNING: Resource survived UnLoadWorld : lua\achievements.lua (Scripts), #1
WARNING: Resource survived UnLoadWorld : sounds/combat (FSBResource), #1
WARNING: Resource survived UnLoadWorld : sounds/all_for_debug (FSBResource), #1
WARNING: Resource survived UnLoadWorld : sounds/global_effects (FSBResource), #1
WARNING: Resource survived UnLoadWorld : sounds/footsteps (FSBResource), #1
WARNING: Resource survived UnLoadWorld : sounds/ui (FSBResource), #1
WARNING: Resource survived UnLoadWorld : <mysterious overhead> (FaceFX), #0
WARNING: Resource survived UnLoadWorld : sounds\pc\combat.fsb (MemoryStreams), #1
WARNING: Resource survived UnLoadWorld : texture_dummy_always_loaded.zct (MemoryStreams), #1
WARNING: Resource survived UnLoadWorld : lua\gameplay_base.lua (Scripts), #1
WARNING: Resource survived UnLoadWorld : lua\init_lua.lua (Scripts), #1
WARNING: Resource survived UnLoadWorld : lua/effect_support/effect_definitions.lua (Scripts), #1
WARNING: Resource survived UnLoadWorld : lua\achievements.lua (Scripts), #1
WARNING: Resource survived UnLoadWorld : sounds/combat (FSBResource), #1
WARNING: Resource survived UnLoadWorld : sounds/all_for_debug (FSBResource), #1
WARNING: Resource survived UnLoadWorld : sounds/global_effects (FSBResource), #1
WARNING: Resource survived UnLoadWorld : sounds/footsteps (FSBResource), #1
WARNING: Resource survived UnLoadWorld : sounds/ui (FSBResource), #1
WARNING: Resource survived UnLoadWorld : <mysterious overhead> (FaceFX), #0
WARNING: Resource survived UnLoadWorld : sounds\pc\combat.fsb (MemoryStreams), #1
WARNING: Resource survived UnLoadWorld : texture_dummy_always_loaded.zct (MemoryStreams), #1
WARNING: Resource survived UnLoadWorld : sounds/combat (FSBResource), #1
WARNING: Resource survived UnLoadWorld : sounds/all_for_debug (FSBResource), #1
WARNING: Resource survived UnLoadWorld : sounds/global_effects (FSBResource), #1
WARNING: Resource survived UnLoadWorld : sounds/footsteps (FSBResource), #1
WARNING: Resource survived UnLoadWorld : sounds/ui (FSBResource), #1
WARNING: Resource survived UnLoadWorld : <mysterious overhead> (FaceFX), #0
WARNING: Resource survived UnLoadWorld : sounds\pc\combat.fsb (MemoryStreams), #1
Dump resources...
name='sounds/combat' category='FSBResource' #ref=1, ptr=0x07FEF3F8
name='sounds/all_for_debug' category='FSBResource' #ref=1, ptr=0x07FEF878
name='sounds/global_effects' category='FSBResource' #ref=1, ptr=0x07FEF578
name='sounds/footsteps' category='FSBResource' #ref=1, ptr=0x07FEF218
name='sounds/ui' category='FSBResource' #ref=1, ptr=0x07FEF758
name='<mysterious overhead>' category='FaceFX' #ref=0, ptr=0x08169158
WARNING: 6 resource leaks! (see list above)

Windows 11 Home here, trying the latest offline installer, no Galaxy installed nor in use.

I think I have the same, or similar, issue, albeit my log file differs somewhat from the OP's.
I think in my case these are the important lines in the log file:

Initialising video driver: 0
Setting screen mode to x:1920 / y:1080 / frontbuffer bpp:32 / refresh:0
Screen Mode is fullscreen
WARNING: Could not set screen mode (error:-2).
WARNING: Unable to initialize video mode
Could not set screen mode (error:-2).

So the game does nothing when I try to launch it, no error or anything, nothing appears. The demonicon executable appears to Task Manager but disappears from there.

This is a Lenovo laptop with both Radeon graphics and NVidia discrete GPU. I think I have set in the NVidia options for it to always prefer using NVidia as the GPU. The laptop is connected to an external monitor and is using it as the primary and only screen (no several monitors or screens in use at the same time).

I guess I need to try different options like whether Radeon graphics works or if the monitor is disconnected etc... I think I haven't updated the graphics drivers for awhile either, maybe I should try that too.

In the meantime, I could also try if I have any better success on another laptop.

You seem to have the same error in the log file as me.

Are you playing on a laptop, what kind of laptop, are you using an external monitor, are you using several screens at the same time etc.? Are you using Galaxy or installing the game with an offline installer?

I just need to test different combinations and options, also maybe try if the same issue is reproducible on the other Windows 10 laptop.

And maybe also try an older version of the offline installer, if I still have one available (possibly I do).

On my older Windows 10 Pro laptop the game seems to run fine.
It is otherwise somewhat similar setup, ie. NVidia discrete GPU, 1920x1080 resolution, connected to an external monitor etc.

I didn't find any tips on PC Gaming Wiki, googling for the error leads to some Steam discussions mainly, need to check if there are any tips.

I'm on a desktop, I have a second monitor(my TV) I keep it off for the majority of the times tough, and I'm using Galaxy

Ok so this isn't laptop specific (e.g. due to having both an integrated GPU and a discrete CPU, and the game having problems deciding which to use or one of them not working).

Good thing anyway your issue was reproduced, I will try to see if I get it running on my problematic laptop so that I could also run it there. And if such fix is found, maybe it needs to be reported both to GOG and PC Gaming Wiki (which has an entry for this game, but no issues/fixes listed).

Which graphics card do you have?

I haven't yet found any fix for this. Things I've tried so far:

1. I've installed the game on three separate laptops, Win10 Pro, Win11 Pro and Win11 Home laptop. The game works fine on the first two laptops but doesn't launch at all on the Win11 Home laptop.

2. I've tried both the newer setup_demonicon_1.1_(45946) and earlier setup_demonicon_1.1_(45947) versions. No difference there, both versions fail similarly on the third laptop.

3. I've tried both with only NVidia discrete CPU (disabled the Radeon internal graphics chip in UEFI settings), and also with Radeon enabled, both giving preference either to the internal Radeon graphics or the discrete NVidia GPU in the NVidia driver serttings). No difference, it seems to fail similarly in all three cases.

4. I've disabled Windows Defender, no difference.

5. I've tried both with the external monitor, and also disconnecting everything (even the mouse) from the laptop and trying to launch the game on the laptop screen. No difference, still doesn't launch.

6. I've tried to use dgVoodoo2 in case this is some weird compatibility problem with the third laptop's newer NVidia GPU or driver, but it didn't help I am not fully sure dgVoodoo2 was enabled though, I did copy the dll files to the Demonicon game folder as instructed but didn¨'t see any difference, also I am unsure if the game is already using some graphics fix dll of its own anyway.

7. I've updated the NVidia drivers to the latest one, didn't change anything.

8. I have made sure DirectPlay is enabled. It is.

I'm stumped at the moment, no idea what else to try at this point. The reason I asked about your graphics card is that the only real difference I can think of with the two working and one non-working laptop is that the third one has much newer NVidia GPU, RTX 3080, while the others have some over 5 years old NVidia mobile GPUs.

So I am just thinking could there be some issue with newer GPU or too much VRAM (an issue which e.g. GTA IV used to have IIRC) etc.? Then again if there was such an issue with newer GPUs, I'd expect more people to have reported it with Demonicon, also to PC Gaming Wiki...

One thing I still need to test. I noticed the game doesn't create config files under %APPDATA% until you have launched the game successfully once. I need to try to copy the config files from a working PC to the one where it doesn't launch, and see if that makes difference either. EDIT: No it didn't make any difference...

Yeah, I have absolutly no idea on what to do here, I'm just waiting for support to contact me reagarding what to do.

Keep us posted if there is a solution.

I still try to think of something, but kinda shitty problem that it seems to appear only on certain systems, ie. I have the problem on one Windows laptop, but not on two others. Weird.

I am mainly trying to figure out if it is possible to run the game in e.g. a window, would that get me anywhere. Just a thought as the problem appears right after the log says it tries to enter a fullscreen mode.