Usually when this happens, it is the result of a save file corruption.
If you are playing on PC:
You should be able to access your autosaves by pressing F9 on the save select screen. From there, you should be able to find a save file from before the corruption issue occurred. When you do, please continue playing from that save file.
If you're unable to find one, or there are no autosaves available, you will either need to revisit all the locations you have previously visited or start a new save.
If you are playing on Console:
Unfortunately, we're very limited when it comes to what we can do when an issue like this occurs. If you have access to an older version of your save file through your Cloud storage, I would recommend trying to load those saves and see if the issue affects them as well. If not, continue from those saves. If those saves are also affected, you will either need to revisit all the locations you have previously visited or start a new save.