There is currently a known issue where Bitdefender can prevent games from launching properly. In addition, it is not notifying players that it is doing so.
This seems to be caused by a false detection from "Advanced Threat Detection" and "Ransomware Remediation".
In order to resolve this issue, you'll have to disable both of these options in Bitdefender. Please note that whitelisting doesn't appear to work at this time.
We're currently investigating the issue further. Thanks for your patience!