Problem with CKEditor Inline

Hello, I'm using "CKEditor Inline 4" and came across some operating problems, the biggest one is when I delete all editing characters in a "button" component and then I can not add more content, opens the edit box over the field but can not put new content, it also occurs at times when I use an elemnto "div", can anyone help me with this problem? I am using the following directive to instantiate CKEditor:

directive('editableText',function($parse){

    //Opções para ckeditor
    var ckOptions = {
        toolbarGroups: [
            { name: 'document',    groups: [ 'mode', 'document' ] },
            { name: 'clipboard',   groups: [ 'clipboard', 'undo' ] },
            '/',
            { name: 'basicstyles', groups: [ 'basicstyles', 'cleanup' ] },
            { name: 'links' },
            { name: 'colors', groups: ['colors'] }
        ],
        disableAutoInline: true,
        disableNativeSpellChecker: false,
        uiColor: '#FAFAFA',
        enterMode : CKEDITOR.ENTER_BR,
        shiftEnterMode: CKEDITOR.ENTER_P

    };

    CKEDITOR.dtd.$editable.span = 1
    CKEDITOR.dtd.$editable.button = 1
    CKEDITOR.dtd.$editable.a = 1

    return {
        restrict: 'A',
        require: 'ngModel',
        link:function(scope,elm,attrs,ngModel){

            //Cria get e set
            var getter = $parse(attrs.ngModel),
            setter = getter.assign;

            //Adiciona atributo content editable = true
            attrs.$set('contenteditable', true);

            //Altera o plugin de salvar do CKEDITOR
            CKEDITOR.plugins.registered['save'] =
            {
                init: function (editor) {
                    editor.addCommand('save',
                        {
                            modes: { wysiwyg: 1, source: 1 },
                            exec: function (editor) {
                                if (editor.checkDirty()) {
                                    var ckValue = editor.getData();
                                    scope.$apply(function () {
                                        setter(scope, ckValue);
                                    });
                                    ckValue = null;
                                }
                            }
                        }
                    );
                }
            };

            ckOptions.on = {
                blur: function (e) {
                    if (e.editor.checkDirty()) {
                        var ckValue = e.editor.getData();
                        scope.$apply(function () {
                            setter(scope, ckValue);
                        });
                        ckValue = null;
                    }
                }
            };

            ckOptions.extraPlugins = 'sourcedialog,panelbutton,floatpanel,colorbutton';
            ckOptions.removePlugins = 'sourcearea';
            var editorAngular = CKEDITOR.inline(elm[0], ckOptions);

            scope.$watch(attrs.editableText, function (value) {
                editorAngular.setData(value);
            });

            editorAngular.on('instanceReady', function() {
                scope.$apply(function() {
                    editorAngular.setData(ngModel.$viewValue);
                });
            });

            CKEDITOR.config.baseFloatZIndex = 99;
            CKEDITOR.config.allowedContent = true;
            CKEDITOR.config.extraAllowedContent = '*(*)';
        }
    };