Hi deadlitch3p0
I'm sorry to hear this has been happening.
Do you hear sound in the background? If so this may be a resolution or refresh issue. Try hitting Alt + Enter to put the game into Windowed mode. This should allow the game to display and then you can change the resolution through the settings menu.
I'd also advise verifying the game files, which will check for missing or corrupt files and replace them. You can do this by clicking on the menu under the game icon in Uplay.
Thank you