Can't sign in to HB with my DK - but Priest works fine?

I've been using HB to level my DK lately, and it's worked fine until today, where it won't even open up HB while being on my DK, but works fine when on my other chars.
Here's the log, maybe someone can help decode it:

Code:

[07:28:33.426 N] Honorbuddy v2.5.8179.697 started.
[07:28:35.206 N] Logging in...
[07:28:37.268 N] Attaching to D3D9
[07:28:37.749 D] System.TypeInitializationException: The type initializer for 'Styx.Helpers.CharacterSettings' threw an exception. ---> System.Xml.XmlException: '.', hexadecimal value 0x00, is an invalid character. Line 1, position 1.
   at System.Xml.XmlTextReaderImpl.Throw(Exception e)
   at System.Xml.XmlTextReaderImpl.Throw(String res, String[] args)
   at System.Xml.XmlTextReaderImpl.ThrowInvalidChar(Char[] data, Int32 length, Int32 invCharPos)
   at System.Xml.XmlTextReaderImpl.ParseRootLevelWhitespace()
   at System.Xml.XmlTextReaderImpl.ParseDocumentContent()
   at System.Xml.XmlTextReaderImpl.Read()
   at System.Xml.XmlReader.MoveToContent()
   at System.Xml.Linq.XElement.Load(XmlReader reader, LoadOptions options)
   at System.Xml.Linq.XElement.Load(String uri, LoadOptions options)
   at Styx.Helpers.Settings..ctor(String settingsPath, String oldSettingsPath)
   at Styx.Helpers.CharacterSettings..ctor()
   at Styx.Helpers.CharacterSettings..cctor()
   --- End of inner exception stack trace ---
   at Honorbuddy.MainWindow.LoadSettings()
   at Honorbuddy.MainWindow.HandleSuccess() --> System.Xml.XmlException: '.', hexadecimal value 0x00, is an invalid character. Line 1, position 1.
   at System.Xml.XmlTextReaderImpl.Throw(Exception e)
   at System.Xml.XmlTextReaderImpl.Throw(String res, String[] args)
   at System.Xml.XmlTextReaderImpl.ThrowInvalidChar(Char[] data, Int32 length, Int32 invCharPos)
   at System.Xml.XmlTextReaderImpl.ParseRootLevelWhitespace()
   at System.Xml.XmlTextReaderImpl.ParseDocumentContent()
   at System.Xml.XmlTextReaderImpl.Read()
   at System.Xml.XmlReader.MoveToContent()
   at System.Xml.Linq.XElement.Load(XmlReader reader, LoadOptions options)
   at System.Xml.Linq.XElement.Load(String uri, LoadOptions options)
   at Styx.Helpers.Settings..ctor(String settingsPath, String oldSettingsPath)
   at Styx.Helpers.CharacterSettings..ctor()
   at Styx.Helpers.CharacterSettings..cctor()
[07:28:37.475 N] Attached to WoW with ID 5388
[07:28:37.749 D] System.TypeInitializationException: The type initializer for 'Styx.Helpers.CharacterSettings' threw an exception. ---> System.Xml.XmlException: '.', hexadecimal value 0x00, is an invalid character. Line 1, position 1.
   at System.Xml.XmlTextReaderImpl.Throw(Exception e)
   at System.Xml.XmlTextReaderImpl.Throw(String res, String[] args)
   at System.Xml.XmlTextReaderImpl.ThrowInvalidChar(Char[] data, Int32 length, Int32 invCharPos)
   at System.Xml.XmlTextReaderImpl.ParseRootLevelWhitespace()
   at System.Xml.XmlTextReaderImpl.ParseDocumentContent()
   at System.Xml.XmlTextReaderImpl.Read()
   at System.Xml.XmlReader.MoveToContent()
   at System.Xml.Linq.XElement.Load(XmlReader reader, LoadOptions options)
   at System.Xml.Linq.XElement.Load(String uri, LoadOptions options)
   at Styx.Helpers.Settings..ctor(String settingsPath, String oldSettingsPath)
   at Styx.Helpers.CharacterSettings..ctor()
   at Styx.Helpers.CharacterSettings..cctor()
   --- End of inner exception stack trace ---
   at Honorbuddy.MainWindow.LoadSettings()
   at Honorbuddy.MainWindow.HandleSuccess() --> System.Xml.XmlException: '.', hexadecimal value 0x00, is an invalid character. Line 1, position 1.
   at System.Xml.XmlTextReaderImpl.Throw(Exception e)
   at System.Xml.XmlTextReaderImpl.Throw(String res, String[] args)
   at System.Xml.XmlTextReaderImpl.ThrowInvalidChar(Char[] data, Int32 length, Int32 invCharPos)
   at System.Xml.XmlTextReaderImpl.ParseRootLevelWhitespace()
   at System.Xml.XmlTextReaderImpl.ParseDocumentContent()
   at System.Xml.XmlTextReaderImpl.Read()
   at System.Xml.XmlReader.MoveToContent()
   at System.Xml.Linq.XElement.Load(XmlReader reader, LoadOptions options)
   at System.Xml.Linq.XElement.Load(String uri, LoadOptions options)
   at Styx.Helpers.Settings..ctor(String settingsPath, String oldSettingsPath)
   at Styx.Helpers.CharacterSettings..ctor()
   at Styx.Helpers.CharacterSettings..cctor()