Here's the patch notes copied right from Steam:
We have heard your concerns about being victims of deviant behavior while playing online multiplayer, we have released a patch solving some of the issues you can encounter. Other updates will follow to continue this work, we will keep you posted in due times!
Today’s update have solved the following issues you may encounter in the Online Mode:
- Being sent immediately to your world
- Being sent to the Firelink Shrine
- Being changed in full Dragon Body Status
We’d also like to remind you that our Server Team is checking all the accounts before penalizing players. If you received an “Invalid Data” message, please refer to the following article:https://support.bandainamcoent.com/index.php?/Knowledgebase/Article/View/507/458/dark-souls-iii---restrictions-and-warning-messages-what-do-they-mean. Players that fall victim of online issues will not be penalized if they are innocent.
The patch is small, only 41mb, and could be a great step for players who are being victimized by folks determined to ruin game play for the rest of us if in fact it does combat the quote "deviant behavior."
I've yet to run across any of this kind of thing myself thank goodness, but it's still recommended that you back up your save file from time to time.
The default path is: C:\Users\Your-username\AppData\Roaming\DarkSoulsIII\
You'll probably have to make Windows show hidden items to see the appdata folder and once you're in you'll be looking for the SL2 file extension. Just make a copy of that and rename it (example: DS30000_old.sl2) or something and that'll back up your save file in case something does happen. This way you can re-load and maybe lose only a couple of hours instead of a whole character or more.