Hello DML.ALE_D-C18, thanks for posting and welcome to the forum.
MSI Afterburner is one of the programs along with Dragon Centre we recommend closing when playing the game as we generally recommend against overclocking your system whilst playing our games and prefer players to use their stock settings.
Please check if you have any of the following programs running in the background, on your PC using Task Manager -
Full Screen Game Overlays - Overwolf / Geforce Experience
VoIP and Chat services - TeamSpeak / Mumble / Discord / Skype / Raptr
RGB controllers - Razer Synapse / SteelSeries Engine / Logitech G Hub / Corsair iCue
Overclocking Software - EVGA Precision X / MSI Afterburner / RivaTuner / ASUS GPU Tweak / ASUS Smart Doctor / Gamer OSD
Hardware monitoring - MSI Kombuster / Fraps / MSI Dragon Center
Streaming software - OBS, Xsplit Gamecaster
Peer to Peer software - BitTorrent / uTorrent
VPN - Hamachi
- Press the Ctrl, Shift and Esc key on your keyboard to bring up Task Manager
- Launch the app then navigate to the 'Start Up' programs tab
- Right click on any program or software that might be conflicting with the game such as the type of programs listed above and select 'Disable'
- Restart the computer then try launching the game from Ubisoft Connect
Please let me know how you get on after testing the game and checking you have no extra programs running in the background.