First things first, would you mind providing a copy of your output_log, located in Steam\steamapps\common\Chronicle\Chronicle_Data please? It'd be helpful to see if any errors are being printed there.

That being said, there is a way to reset graphics. There is no config file as such - the graphics settings and player choices are all stored as registry keys. In the start menu, type regedit to open the Registry Editor. Look in HKEY_CURRENT_USER -> Software -> Jagex Ltd -> Chronicle - Runescape Legends.

These are pretty much all the game settings - you can see from the key names, such as 'soundToggle' or 'playerPrefFullscreen'. Simply delete all the keys, aside from the one at the top labelled as (Default).

I took a screenshot of the values: https://postimg.org/image/dzdw803xj/

To be on the safe side, make sure you back the keys up first, by right clicking on Chronicle - Runescape Legends (on the left side of the editor), clicking 'Export', and saving the keys somewhere. It means you've at least got a backup, and you can simply double click on the exported keys and restore them if need be.

After deleting all the keys, the next time you boot Chronicle, it'll start up in the default settings for your current hardware. If you check the registry again, you'll find it'll have subsequently written new values. :)

Fixed as of last update so I don't know if they saw my post or just... I have no idea.