GUILayout.TextArea/TextField not working.

not really enough information to help you out here... What exactly is it doing?

Exactly. What code is around this line? GUILayout uses layouting groups, so it depends on the other elements how big and where the area / field will show up.

  "I can't seem to find out what's wrong here."

sorry, but we can't either...

Here's the whole OnGUI code (it's a file browser) :

GUILayout.BeginArea(new Rect ( 30, 30, Screen.width-60, Screen.height-60), "Enregistrer sous...", (GUIStyle)"box");

         GUILayout.Space(30);
         
         GUI.skin.box.alignment = TextAnchor.$$anonymous$$iddleLeft;
         
         // top toolbar
         GUILayout.BeginHorizontal();
             // Display current directory
             GUILayout.Box(_currentDir);
         
             // Goto parent button
             DirectoryInfo parent = new DirectoryInfo(_currentDir).Parent;
             if ( parent == null || !parent.FullName.Contains( _viewScope ) )
                     GUI.enabled = false;
             if ( GUILayout.Button(_parentTex,GUILayout.Width(GUI.skin.button.fixedHeight) ) ) 
                 RegisterNewLocation(new DirectoryInfo(_currentDir).Parent.FullName);
             GUI.enabled = true;
     
             // Previous button
             if ( _historyIndex <= 0 ) GUI.enabled = false;
             if ( GUILayout.Button(_previousTex,GUILayout.Width(GUI.skin.button.fixedHeight) ) ) 
                 _currentDir = _history[--_historyIndex];
             GUI.enabled = true;
             
             // Next button
             if ( _historyIndex >= _history.Count-1 ) GUI.enabled = false;
             if ( GUILayout.Button(_nextTex,GUILayout.Width(GUI.skin.button.fixedHeight) ) ) 
                 _currentDir = _history[++_historyIndex];
             GUI.enabled = true;
         GUILayout.EndHorizontal();
     
         //Debug.Log("History Index : " + _historyIndex + "/ History nb elements : " + _history.Count);
         
         GUI.skin.box.alignment = TextAnchor.UpperCenter;
     
         GUILayout.Space(10);
         
         // $$anonymous$$ain panels
         GUILayout.BeginHorizontal();
         
             // DIR VIEW
             _scrollPosDirView = GUILayout.BeginScrollView(_scrollPosDirView, "box", GUILayout.Width(Screen.width*0.25f));
             
             GUILayout.BeginHorizontal();
             GUILayout.Label(_dirTex, GUILayout.Height(GUI.skin.button.fixedHeight), GUILayout.Width(GUI.skin.button.fixedHeight));
             
             if ( _viewScope.Equals(_currentDir) ) GUI.SetNextControlName("SelectedDir");
             
             if ( GUILayout.Button ( new DirectoryInfo(_viewScope).Name ))
             {
                 _currentDir = _viewScope;
             }
             
             GUILayout.EndHorizontal();
             
             GUI.FocusControl("SelectedDir");
             DisplayRecursively(_viewScope, _currentDir);
             GUILayout.EndScrollView();
         
             // FILE VIEW
             _scrollPosFileView = GUILayout.BeginScrollView(_scrollPosFileView, "box");
             DisplayIconView(_currentDir);
             GUILayout.EndScrollView();
         
         GUILayout.EndHorizontal();
         
         GUILayout.Space(5);
         
         // Filename text field
         GUILayout.BeginHorizontal();
             GUILayout.Label("Nom du fichier : ", GUILayout.Width(Screen.width*0.2f) );
             _currentFile = GUILayout.TextArea(_currentFile);
         GUILayout.EndHorizontal();    
     
         // Error Box
         GUILayout.Box(_error);
     
         // Confirm buttons
         GUILayout.BeginHorizontal();
             GUILayout.Space(Screen.width*0.6f);
             if(GUILayout.Button("O$$anonymous$$"))
             {
                 
             }
             if(GUILayout.Button("Cancel"))
             {
                 _callback("");
                 Destroy(this.gameObject);
             }
         GUILayout.EndHorizontal();
     
     
     GUILayout.EndArea();

I think I found what part of my code is wrong :

 // $$anonymous$$ain panels
        GUILayout.BeginHorizontal();
 
          // DIR VIEW
          _scrollPosDirView = GUILayout.BeginScrollView(_scrollPosDirView, "box", GUILayout.Width(Screen.width*0.25f));
 
          GUILayout.BeginHorizontal();
          GUILayout.Label(_dirTex, GUILayout.Height(GUI.skin.button.fixedHeight), GUILayout.Width(GUI.skin.button.fixedHeight));
 
          if ( _viewScope.Equals(_currentDir) ) GUI.SetNextControlName("SelectedDir");
 
          if ( GUILayout.Button ( new DirectoryInfo(_viewScope).Name ))
          {
           _currentDir = _viewScope;
          }
 
          GUILayout.EndHorizontal();
 
          GUI.FocusControl("SelectedDir");
          DisplayRecursively(_viewScope, _currentDir);
          GUILayout.EndScrollView();
 
          // FILE VIEW
          _scrollPosFileView = GUILayout.BeginScrollView(_scrollPosFileView, "box");
          DisplayIconView(_currentDir);
          GUILayout.EndScrollView();
 
        GUILayout.EndHorizontal();

I still don't know how to solve that issue, but if I delete that part, my TextField works just fine. There must definitely be something with the GUI system that I don't understand.