Config wont update

hi i get this error

 [Ruster.NET] System.NullReferenceException: Object reference not set to an instance of an object at Oxide.Plugins.RusterNET+RusterBrowser.DrawPost (Oxide.Game.Rust.Cui.CuiElementContainer container, System.String parent, Oxide.Plugins.RusterNET+RusterFeed feed, Oxide.Plugins.RusterNET+RusterFeed+RusterPost post, System.Single anchorMin, System.Single anchorMax, System.Int32& lineMultiplier, System.Boolean allowProfilePreviews, System.Boolean showReplies, System.Boolean showPhoto) [0x004e8] in <45b0a1b7497344cd960f3416a276609d>:0

I have added the Imgur ID and set Currency to 2 But i cannot upload pictures says i haven't set the ID and still says scrap as currency instead of economy 

& cannot list any item for sale

Keeps Resetting the config back to default

{ "LogLevel": -1, "DataType": 0, "UniqueId (Must not be null/empty)": "defaultid", "Ads": { "AdvertPrice24h": 5000, "AdvertPriceMultiplier1w": 6.5 }, "Tax": { "Amount": 0.9 }, "Marketplace": { "MaximumStackSizeEachItem (-1 = Default stacksize for the item)": -1, "MaximumStackSizeWholeStack (-1 = Default stacksize for the item)": -1, "MinimumPrice": 0, "MaximumPrice": 10000000000, "BlacklistedItems": [ "photo" ] }, "Look": { "AdminNameColor": "#de3535", "ModeratorNameColor": "#a3de35" }, "DMs": { "MustBeFriendsToDM": true, "DeleteOwnMessagesCooldown": 1800.0 }, "Notifications": { "VerticalOffset": 0.0 }, "Sounds": { "FFMPEGPath": "", "PlayStartup": true, "PlayBeeps": true, "PlayLikes": true, "PlayDislikes": true }, "PhotographUpload": { "ImgurClientId": "4f99625fc094f53" }, "Cooldown": { "ButtonPress": 0.5, "BusinessCardCreation": 60.0, "RustPlusNotifications": 4.0 }, "Currency": { "ItemShortname": "scrap", "ItemSkinId": 0, "Currency Type (0 = Item, 1 = ServerRewards, 2 = Economics": 2 }, "Profanity": { "BannedWords": [ "nigger", "chink", "blackie", "cunt", "faggot" ], "BannedWordReplacements": [ "plushie", "bubble", "cutie", "puff", "kitten" ] }, "Sql": { "Port": 3306, "Hostname": "localhost", "Database": "RusterNET", "Username": "root", "Password": null, "Table": "RusterNET" }, "Localisation": { "DefaultLanguage": "en-GB", "Languages": [ { "Name": "English (UK)", "Id": "en-GB", "FlagUrl": "https://flagpedia.net/data/flags/w160/gb.png" } ] } }

so its not the config?