You will need to verify your files on steam - this issue has occurred for several people i know.
Verify files. and restart your PC fixed for all of them.
I’m sorry that the game keeps giving the connection error to you!
If you are still running into this issue, please try these steps to see if we can get this working for you:
1-From the Start/Windows Menu, select Settings.
2-Select Network and Internet.
3-In the Status section, under Change your network settings, select Change adapter options.
4-When the Network Connections window opens, right-click your network connection.
5-Select Properties.
Scroll to Internet Protocol version 6. 6-Uncheck the Internet Protocol Version 6 (TCP/IPv6) box.
7-Select OK to save your changes for the selected network adapter.
Also
Press Windows + R, type “firewall.cpl” into the Run window, and then press Enter.
Click Allow an app or feature through Windows Firewall and then click Change settings.
Look for the game in the list of allowed apps and features. If it’s present, make sure it’s checked, and that both the Private and Public columns have a check mark. If the app is missing from the list, you need to add it.
Restart your router and modem, then try launching the game again.
Also please try to set those ports:
TCP: 80.443
UDP: 33435
Try launching the game again. A PC restart may be necessary.
This should fix the issue. However if the problem persists don’t hesitate to contact back to find a fix for your particular issue.