Good morning !
Installed NET-framework manually from your link. Not work.
SkyEliteServer.exe CMD result:
Microsoft Windows [Versión 10.0.19043.1165]
(c) Microsoft Corporation. Todos los derechos reservados.
C:\Windows\system32>cd "C:\Program Files\SkyElite for MFS2020\Server"
C:\Program Files\SkyElite for MFS2020\Server>SkyEliteServer.exe
Log located at: C:\Program Files\SkyElite for MFS2020\Data\Log.txt
2021/09/15 10:48:13:1458 [INFO]: OS Microsoft Windows 10.0.19043
2021/09/15 10:48:13:1693 [INFO]: SkyElite for MSFS 1.2
2021/09/15 10:48:13:1843 [INFO]: InitConfig() started
2021/09/15 10:48:13:2003 [INFO]: Startup working directory: C:\Program Files\SkyElite for MFS2020\Server
2021/09/15 10:48:13:2160 [INFO]: Startup assembly location: C:\Program Files\SkyElite for MFS2020\Server
2021/09/15 10:48:13:2319 [INFO]: Working directory set to: C:\Program Files\SkyElite for MFS2020\Server
2021/09/15 10:48:13:2479 [INFO]: root flag: True
2021/09/15 10:48:13:2638 [INFO]: InitConfig() ConfigurationBuilder started
2021/09/15 10:48:13:2798 [INFO]: Finding database from: C:\Program Files\SkyElite for MFS2020\Server
2021/09/15 10:48:13:2957 [INFO]: Database found at: C:\Program Files\SkyElite for MFS2020\Data\skyelite.db
2021/09/15 10:48:13:7386 [INFO]: DATABASE VERSION: 4
2021/09/15 10:48:13:7556 [INFO]: Checking database updates
2021/09/15 10:48:13:7695 [INFO]: Database is up to date
2021/09/15 10:48:13:7847 [INFO]: INSTALLATIONID 2E4328C2F89647AB93FBAAAF66B737C5
2021/09/15 10:48:13:8000 [INFO]: LICENSE TYPE: DEMO VERSION
2021/09/15 10:48:13:8149 [INFO]: SkyElitePads not started, midi devices not found.
2021/09/15 10:48:13:8309 [INFO]: SkyElitePads midi devices not found.
2021/09/15 10:48:13:8469 [INFO]: Checking presets
Unhandled exception. System.TypeInitializationException: The type initializer for 'SkyConnect.staticSkyInterface' threw an exception.
---> System.Runtime.InteropServices.COMException (0x80040154): Retrieving the COM class factory for component with CLSID {6BF52A52-394A-11D3-B153-00C04F79FAA6} failed due to the following error: 80040154 Clase no registrada (0x80040154 (REGDB_E_CLASSNOTREG)).
at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean wrapExceptions, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& hasNoDefaultCtor)
at System.RuntimeType.CreateInstanceDefaultCtorSlow(Boolean publicOnly, Boolean wrapExceptions, Boolean fillCache)
at System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, Boolean wrapExceptions)
at System.Activator.CreateInstance(Type type, Boolean nonPublic, Boolean wrapExceptions)
at System.Activator.CreateInstance(Type type)
at SkyMediaPlayer.SkyPlayer..ctor() in D:\MSFS2020-Developer\SkyElite\SkyMediaPlayer\SkyMediaPlayer\SkyMediaPlayer\SkyMediaPlayer.cs:line 13
at SkyConnect.staticSkyInterface..cctor() in D:\MSFS2020-Developer\SkyElite\SkyEliteServer.Core31\SkyEliteServer\SkyConnect\SkyInterface.cs:line 36
--- End of inner exception stack trace ---
at SkyEliteServer.Program.Main(String[] args) in D:\MSFS2020-Developer\SkyElite\SkyEliteServer.Core31\SkyEliteServer\Program.cs:line 110
2021/09/15 10:48:13:8628 [INFO]: music.data preset skipped.
2021/09/15 10:48:13:8779 [INFO]: maps.data preset skipped.
2021/09/15 10:48:13:8936 [INFO]: Presets done.
2021/09/15 10:48:13:9091 [INFO]: GetMaps initialization
2021/09/15 10:48:13:9197 [INFO]: GetJsonDataFromFile loading from: C:\Program Files\SkyElite for MFS2020\Data\maps.data
2021/09/15 10:48:14:2432 [INFO]: GetMaps initialization
C:\Program Files\SkyElite for MFS2020\Server>