I ahve no idea why this happens.
Ideas
That usually happens when there is an issue with the anticheat.
Either it's become corrupted and needs to be repaired (link below will provide steps on re-installing) or there's another program running on your computer being flagged and causing a false positive.
How to install and troubleshoot EA Javelin Anticheat on your PC
Hi,
I have tried uninstalling anticheat and reinstalling, however the same issue appears. I have uninstalled the game and reinstalled it to refresh all game files but the same thing still happens.