[Help] Translation mod error

[Corgi_CoCo]

Hello guys,

I'm trying to translate this game into Korean, following 'Creating/Using Translation Files [Updated August 22nd, 2017] - [Oxygen Not Included] - Mods and Tools - Klei Entertainment Forums' <- this post, but it get down if I subscribe my mod and try to change the language in the game.

Error in LanguageOptionsMenu.LanguageOptionsScreen.OnSpawn 
System.NullReferenceException: Object reference not set to an instance of an object
  at Localization.GetFontName (System.String[] lines) [0x00032] in <1c7e9ccb4aa844e2be4538990aabf98e>:0 
  at LanguageOptionsScreen.RebuildUGCButtons () [0x0007f] in <1c7e9ccb4aa844e2be4538990aabf98e>:0 
  at LanguageOptionsScreen.RebuildScreen () [0x0007c] in <1c7e9ccb4aa844e2be4538990aabf98e>:0 
  at LanguageOptionsScreen.UpdateMods (System.Collections.Generic.IEnumerable`1[T] added, System.Collections.Generic.IEnumerable`1[T] updated, System.Collections.Generic.IEnumerable`1[T] removed, System.Collections.Generic.IEnumerable`1[T] loaded_previews) [0x0009a] in <1c7e9ccb4aa844e2be4538990aabf98e>:0 
  at SteamUGCService.AddClient (SteamUGCService+IClient client) [0x0005e] in <1c7e9ccb4aa844e2be4538990aabf98e>:0 
  at LanguageOptionsScreen.OnActivate () [0x0002d] in <1c7e9ccb4aa844e2be4538990aabf98e>:0 
  at KScreen.Activate () [0x00017] in <8c239b169b544cce8b8bc7ddd2d09e10>:0 
  at KScreen.OnSpawn () [0x0004e] in <8c239b169b544cce8b8bc7ddd2d09e10>:0 
  at LanguageOptionsScreen.OnSpawn () [0x00000] in <1c7e9ccb4aa844e2be4538990aabf98e>:0 
  at KMonoBehaviour.Spawn () [0x0005d] in <8c239b169b544cce8b8bc7ddd2d09e10>:0 

  at UnityEngine.Debug.LogError (System.Object message, UnityEngine.Object context) [0x00000] in <72b60a3dd8cd4f12a155b761a1af9144>:0 
  at Debug.LogError (System.Object obj, UnityEngine.Object context) [0x00000] in <8c239b169b544cce8b8bc7ddd2d09e10>:0 
  at DebugUtil.LogErrorArgs (UnityEngine.Object context, System.Object[] objs) [0x00000] in <8c239b169b544cce8b8bc7ddd2d09e10>:0 
  at DebugUtil.LogException (UnityEngine.Object context, System.String errorMessage, System.Exception e) [0x00000] in <8c239b169b544cce8b8bc7ddd2d09e10>:0 
  at KMonoBehaviour.Spawn () [0x00000] in <8c239b169b544cce8b8bc7ddd2d09e10>:0 
  at KMonoBehaviour.Start () [0x00000] in <8c239b169b544cce8b8bc7ddd2d09e10>:0 
Build: U42-514967-V

This is the log what I got. 

I think I need to specify a font name but I don't know where to change it.

Please anyone help me with my problem?

[Sanchozz]

show us your strings.po file

[Corgi_CoCo]

Sorry, I solved it. My strings.po file named by string.po file, also I changed preview image's extansion .jpeg to png.

Thank you for your reply