diff --git a/RhSolutions.AddIn/Controllers/RibbonController.cs b/RhSolutions.AddIn/Controllers/RibbonController.cs
index 140ba10..b5edde0 100644
--- a/RhSolutions.AddIn/Controllers/RibbonController.cs
+++ b/RhSolutions.AddIn/Controllers/RibbonController.cs
@@ -15,6 +15,7 @@ namespace RhSolutions.Controllers;
 public class RibbonController : ExcelRibbon
 {
     private static IRibbonUI ribbonUi;
+    private static bool _workbookIsValid;
 
     public override string GetCustomUI(string RibbonID)
     {
@@ -81,17 +82,9 @@ public class RibbonController : ExcelRibbon
         }
     }
 
-    public bool GetConvertEnabled(IRibbonControl control)
-    {
-        if (RhSolutionsAddIn.Excel.ActiveWorkbook == null)
-            return false;
-
-        else
-        {
-            Worksheet worksheet = RhSolutionsAddIn.Excel.ActiveWorkbook.ActiveSheet;
-            return worksheet.IsValidSource();
-        }
-    }
+    public bool GetConvertEnabled(IRibbonControl control) => _workbookIsValid;
+    public bool GetDxfEnabled(IRibbonControl control) => _workbookIsValid;
+    public bool GetGuessEnabled(IRibbonControl control) => RhSolutionsAddIn.Excel.ActiveWorkbook == null ? false : !_workbookIsValid;
 
     public bool GetExportEnabled(IRibbonControl control)
     {
@@ -105,30 +98,6 @@ public class RibbonController : ExcelRibbon
         }
     }
 
-    public bool GetDxfEnabled(IRibbonControl control)
-    {
-        if (RhSolutionsAddIn.Excel.ActiveWorkbook == null)
-            return false;
-
-        else
-        {
-            Worksheet worksheet = RhSolutionsAddIn.Excel.ActiveWorkbook.ActiveSheet;
-            return worksheet.IsValidSource();
-        }
-    }
-
-    public bool GetGuessEnabled(IRibbonControl control)
-    {
-        if (RhSolutionsAddIn.Excel.ActiveWorkbook == null)
-            return false;
-
-        else
-        {
-            Worksheet worksheet = RhSolutionsAddIn.Excel.ActiveWorkbook.ActiveSheet;
-            return !worksheet.IsValidSource();
-        }
-    }
-
     public string GetVersionLabel(IRibbonControl control)
     {
         string version = Assembly.GetExecutingAssembly().GetName().Version.ToString();
@@ -140,4 +109,16 @@ public class RibbonController : ExcelRibbon
         string name = RhSolutionsAddIn.Configuration.GetPriceListFileName();
         return string.IsNullOrEmpty(name) ? "Шаблонный файл" : name;
     }
+
+    public static void UpdateWorkbookValidation()
+    {
+        if (RhSolutionsAddIn.Excel.ActiveWorkbook == null)
+            _workbookIsValid = false;
+
+        else
+        {
+            Worksheet worksheet = RhSolutionsAddIn.Excel.ActiveWorkbook.ActiveSheet;
+            _workbookIsValid = worksheet.IsValidSource();
+        }
+    }
 }
diff --git a/RhSolutions.AddIn/Tools/EventsUtil.cs b/RhSolutions.AddIn/Tools/EventsUtil.cs
index 92aa717..07da3e5 100644
--- a/RhSolutions.AddIn/Tools/EventsUtil.cs
+++ b/RhSolutions.AddIn/Tools/EventsUtil.cs
@@ -16,35 +16,25 @@ namespace RhSolutions.Tools
         public static void Initialize()
         {
             RhSolutionsAddIn.Excel.SheetSelectionChange += RefreshExportButton;
-            RhSolutionsAddIn.Excel.SheetActivate += RefreshConvertButton;
-            RhSolutionsAddIn.Excel.SheetActivate += RefreshDxfButton;
-            RhSolutionsAddIn.Excel.SheetActivate += RefreshGuessButton;
-            RhSolutionsAddIn.Excel.WorkbookActivate += RefreshConvertButton;
-            RhSolutionsAddIn.Excel.WorkbookActivate += RefreshDxfButton;
-            RhSolutionsAddIn.Excel.WorkbookActivate += RefreshGuessButton;
+            RhSolutionsAddIn.Excel.SheetActivate += RefreshButtons;
+            RhSolutionsAddIn.Excel.WorkbookActivate += RefreshButtons;
             RhSolutionsAddIn.Configuration.OnSettingsChange += RefreshSettingTitle;
         }
 
         public static void Uninitialize()
         {
             RhSolutionsAddIn.Excel.SheetSelectionChange -= RefreshExportButton;
-            RhSolutionsAddIn.Excel.SheetActivate -= RefreshConvertButton;
-            RhSolutionsAddIn.Excel.SheetActivate -= RefreshDxfButton;
-            RhSolutionsAddIn.Excel.SheetActivate -= RefreshGuessButton;
-            RhSolutionsAddIn.Excel.WorkbookActivate -= RefreshConvertButton;
-            RhSolutionsAddIn.Excel.WorkbookActivate -= RefreshDxfButton;
-            RhSolutionsAddIn.Excel.WorkbookActivate -= RefreshGuessButton;
+            RhSolutionsAddIn.Excel.SheetActivate -= RefreshButtons;
+            RhSolutionsAddIn.Excel.WorkbookActivate -= RefreshButtons;
             RhSolutionsAddIn.Configuration.OnSettingsChange -= RefreshSettingTitle;
         }
 
-        private static void RefreshConvertButton(object sh)
+        private static void RefreshButtons(object sh)
         {
+            RibbonController.UpdateWorkbookValidation();
             RibbonController.RefreshControl("convert");
-        }
-
-        private static void RefreshDxfButton(object sh)
-        {
             RibbonController.RefreshControl("dxfexport");
+            RibbonController.RefreshControl("Guessexport");
         }
 
         private static void RefreshExportButton(object sh, Range target)
@@ -52,11 +42,6 @@ namespace RhSolutions.Tools
             RibbonController.RefreshControl("export");
         }
 
-        private static void RefreshGuessButton(object sh)
-        {
-            RibbonController.RefreshControl("Guessexport");
-        }
-
         private static void RefreshSettingTitle(object sender, SettingChangingEventArgs e)
         {
             RibbonController.RefreshControl("setPriceList");