In some cases, we've seen that people launching the game will get Access Denied errors.
If is occurring, please try to run the game directly as administrator.
If that doesn't help, please try validating your game's cache via Steam. Instructions are here:
We've also received reports that some antivirus programs are causing this. In this case adding Pyre to your whitelist or "trusted" list may help.
We've also received reports that disabling the One Drive feature on Windows 10 may help.