diff --git a/ClosedXML/Excel/ConditionalFormats/Save/XLCFContainsConverter.cs b/ClosedXML/Excel/ConditionalFormats/Save/XLCFContainsConverter.cs
index 3abf4c3..83ccf67 100644
--- a/ClosedXML/Excel/ConditionalFormats/Save/XLCFContainsConverter.cs
+++ b/ClosedXML/Excel/ConditionalFormats/Save/XLCFContainsConverter.cs
@@ -11,7 +11,7 @@
         public ConditionalFormattingRule Convert(IXLConditionalFormat cf, int priority, XLWorkbook.SaveContext context)
         {
             String val = cf.Values[1].Value;
-            var conditionalFormattingRule = new ConditionalFormattingRule { FormatId = (UInt32)context.DifferentialFormats[cf.Style], Operator = cf.Operator.ToOpenXml(), Text = val, Type = cf.ConditionalFormatType.ToOpenXml(), Priority = priority };
+            var conditionalFormattingRule = new ConditionalFormattingRule { FormatId = (UInt32)context.DifferentialFormats[cf.Style], Operator = ConditionalFormattingOperatorValues.ContainsText, Text = val, Type = cf.ConditionalFormatType.ToOpenXml(), Priority = priority };
 
             var formula = new Formula { Text = "NOT(ISERROR(SEARCH(\"" + val + "\"," + cf.Range.RangeAddress.FirstAddress.ToStringRelative(false) + ")))" };
 
diff --git a/ClosedXML/Excel/ConditionalFormats/Save/XLCFEndsWithConverter.cs b/ClosedXML/Excel/ConditionalFormats/Save/XLCFEndsWithConverter.cs
index 1fa1532..1425fc6 100644
--- a/ClosedXML/Excel/ConditionalFormats/Save/XLCFEndsWithConverter.cs
+++ b/ClosedXML/Excel/ConditionalFormats/Save/XLCFEndsWithConverter.cs
@@ -11,7 +11,7 @@
         public ConditionalFormattingRule Convert(IXLConditionalFormat cf, int priority, XLWorkbook.SaveContext context)
         {
             String val = cf.Values[1].Value;
-            var conditionalFormattingRule = new ConditionalFormattingRule { FormatId = (UInt32)context.DifferentialFormats[cf.Style], Operator = cf.Operator.ToOpenXml(), Text = val, Type = cf.ConditionalFormatType.ToOpenXml(), Priority = priority };
+            var conditionalFormattingRule = new ConditionalFormattingRule { FormatId = (UInt32)context.DifferentialFormats[cf.Style], Operator = ConditionalFormattingOperatorValues.EndsWith, Text = val, Type = cf.ConditionalFormatType.ToOpenXml(), Priority = priority };
 
             var formula = new Formula { Text = "RIGHT(" + cf.Range.RangeAddress.FirstAddress.ToStringRelative(false) + "," + val.Length.ToString() + ")=\"" + val + "\"" };
 
diff --git a/ClosedXML/Excel/ConditionalFormats/Save/XLCFNotContainsConverter.cs b/ClosedXML/Excel/ConditionalFormats/Save/XLCFNotContainsConverter.cs
index 86dcee8..6d86b12 100644
--- a/ClosedXML/Excel/ConditionalFormats/Save/XLCFNotContainsConverter.cs
+++ b/ClosedXML/Excel/ConditionalFormats/Save/XLCFNotContainsConverter.cs
@@ -11,7 +11,7 @@
         public ConditionalFormattingRule Convert(IXLConditionalFormat cf, int priority, XLWorkbook.SaveContext context)
         {
             String val = cf.Values[1].Value;
-            var conditionalFormattingRule = new ConditionalFormattingRule { FormatId = (UInt32)context.DifferentialFormats[cf.Style], Operator = cf.Operator.ToOpenXml(), Text = val, Type = cf.ConditionalFormatType.ToOpenXml(), Priority = priority };
+            var conditionalFormattingRule = new ConditionalFormattingRule { FormatId = (UInt32)context.DifferentialFormats[cf.Style], Operator = ConditionalFormattingOperatorValues.NotContains, Text = val, Type = cf.ConditionalFormatType.ToOpenXml(), Priority = priority };
 
             var formula = new Formula { Text = "ISERROR(SEARCH(\"" + val + "\"," + cf.Range.RangeAddress.FirstAddress.ToStringRelative(false) + "))" };
 
diff --git a/ClosedXML/Excel/ConditionalFormats/Save/XLCFStartsWithConverter.cs b/ClosedXML/Excel/ConditionalFormats/Save/XLCFStartsWithConverter.cs
index 82cfb88..7cee965 100644
--- a/ClosedXML/Excel/ConditionalFormats/Save/XLCFStartsWithConverter.cs
+++ b/ClosedXML/Excel/ConditionalFormats/Save/XLCFStartsWithConverter.cs
@@ -11,7 +11,7 @@
         public ConditionalFormattingRule Convert(IXLConditionalFormat cf, int priority, XLWorkbook.SaveContext context)
         {
             String val = cf.Values[1].Value;
-            var conditionalFormattingRule = new ConditionalFormattingRule { FormatId = (UInt32)context.DifferentialFormats[cf.Style], Operator = cf.Operator.ToOpenXml(), Text = val, Type = cf.ConditionalFormatType.ToOpenXml(), Priority = priority };
+            var conditionalFormattingRule = new ConditionalFormattingRule { FormatId = (UInt32)context.DifferentialFormats[cf.Style], Operator = ConditionalFormattingOperatorValues.BeginsWith, Text = val, Type = cf.ConditionalFormatType.ToOpenXml(), Priority = priority };
 
             var formula = new Formula { Text = "LEFT(" + cf.Range.RangeAddress.FirstAddress.ToStringRelative(false) + "," + val.Length.ToString() + ")=\"" + val + "\"" };
 
diff --git a/ClosedXML/Excel/XLWorkbook_Load.cs b/ClosedXML/Excel/XLWorkbook_Load.cs
index 51e606b..bb05e45 100644
--- a/ClosedXML/Excel/XLWorkbook_Load.cs
+++ b/ClosedXML/Excel/XLWorkbook_Load.cs
@@ -1585,6 +1585,10 @@
             }
         }
 
+        /// <summary>
+        /// Loads the conditional formatting.
+        /// https://msdn.microsoft.com/en-us/library/documentformat.openxml.spreadsheet.conditionalformattingrule%28v=office.15%29.aspx?f=255&MSPPError=-2147217396
+        /// </summary>
         private void LoadConditionalFormatting(ConditionalFormatting conditionalFormatting, XLWorksheet ws, Dictionary<Int32, DifferentialFormat> differentialFormats)
         {
             if (conditionalFormatting == null) return;
@@ -1601,18 +1605,26 @@
                         LoadBorder(differentialFormats[(Int32)fr.FormatId.Value].Border, conditionalFormat.Style.Border);
                         LoadNumberFormat(differentialFormats[(Int32)fr.FormatId.Value].NumberingFormat, conditionalFormat.Style.NumberFormat);
                     }
-                    if (fr.Operator != null)
+
+                    // The conditional formatting type is compulsory. If it doesn't exist, skip the entire rule.
+                    if (fr.Type == null) continue;
+                    conditionalFormat.ConditionalFormatType = fr.Type.Value.ToClosedXml();
+
+                    if (conditionalFormat.ConditionalFormatType == XLConditionalFormatType.CellIs && fr.Operator != null)
                         conditionalFormat.Operator = fr.Operator.Value.ToClosedXml();
-                    if (fr.Type != null)
-                        conditionalFormat.ConditionalFormatType = fr.Type.Value.ToClosedXml();
-                    if (fr.Text != null)
+
+                    if (fr.Text != null && !XLHelper.IsNullOrWhiteSpace(fr.Text))
                         conditionalFormat.Values.Add(GetFormula(fr.Text.Value));
-                    if (fr.Percent != null)
-                        conditionalFormat.Percent = fr.Percent.Value;
-                    if (fr.Bottom != null)
-                        conditionalFormat.Bottom = fr.Bottom.Value;
-                    if (fr.Rank != null)
-                        conditionalFormat.Values.Add(GetFormula(fr.Rank.Value.ToString()));
+
+                    if (conditionalFormat.ConditionalFormatType == XLConditionalFormatType.Top10)
+                    {
+                        if (fr.Percent != null)
+                            conditionalFormat.Percent = fr.Percent.Value;
+                        if (fr.Bottom != null)
+                            conditionalFormat.Bottom = fr.Bottom.Value;
+                        if (fr.Rank != null)
+                            conditionalFormat.Values.Add(GetFormula(fr.Rank.Value.ToString()));
+                    }
 
                     if (fr.Elements<ColorScale>().Any())
                     {