I also faced a similar issue - a java cucumber test trying to interact with an msedgedriver.exe, and then reporting the same error message: "org.openqa.selenium.SessionNotCreatedException: Could not start a new session. Response code 500. Message: session not created: probably user data directory is already in use, please specify a unique value for --user-data-dir argument, or don't use --user-data-dir".

It turns out that the process was running as an administrator on the windows box, rather than using a user account (with AD credentials), and that seemed to cause the issue. When we ran java using a user account, then cucumber was able to interact with the selenium web driver.