First make sure your game meets the minimum requirements
https://paradox.zendesk.com/hc/en-us/sections/200484708-System-Requirements
Please try updating your video card drivers
Nvidia
You can download your up to date drivers here: http://www.geforce.co.uk/drivers
Amd
You can download your up to date drivers from here: http://support.amd.com/en-us
Intel
You can download your up to date drivers here: https://downloadcenter.intel.com/default.aspx
If you have and it still doesn't work, find the stderr.txt in the game folder, and submit a ticket.