The latest Dark Souls 3 patch brought minor tweaks and fixes to the game, but it appears that there's a deeper issue hidden within the confines of the PC community. Players have reported being met with a ban from the game over 'invalid data.'
This error is typically given to those that use cheats, not to legitimate players.
[CAUTION] INVALID GAME DATA HAS BEEN DETECTED
Invalid game data has been detected on your account. The use of invalid data during gameplay is a violation of the online service end user license agreement. You will be penalized if you continue playing with invalid data. Please take this opportunity to remove the invalid data from your system/account and discontinue further use.
Reports across various Reddit threads and Steam discussions have been filled with players claiming that they didn't modify the game files in any way or download a cheat client, but have been hit with the error. Players have claimed to be free of any downloaded software, save for Xbox and DualShock 4 controller software, and still get hit from the error.
It appears that the issue most commonly occurs after players have played offline, saving, then attempting to connect to the servers and download their game.
While frustrating, this is not a new issue when it comes to the Dark Souls franchise.
When Dark Souls 2 was released players were banned for any type of file that was in addition to the base game. Players using DualShock and Xbox controller drivers, NVIDIA FPS overlay and recording, automatic back up solutions, streaming software, SweetFX, ENB and more.
It appears as though From Soft is doing their best to make sure that there are no cheaters in online play, but being a bit too aggressive with who they ban.