diff --git a/src/modules/launcher/Plugins/Microsoft.Plugin.Calculator/Main.cs b/src/modules/launcher/Plugins/Microsoft.Plugin.Calculator/Main.cs
index fb848b8e6c..29cda2497d 100644
--- a/src/modules/launcher/Plugins/Microsoft.Plugin.Calculator/Main.cs
+++ b/src/modules/launcher/Plugins/Microsoft.Plugin.Calculator/Main.cs
@@ -6,6 +6,7 @@ using System.Text.RegularExpressions;
 using System.Threading;
 using System.Windows;
 using Mages.Core;
+using Wox.Infrastructure.Logger;
 using Wox.Plugin;
 
 namespace Microsoft.Plugin.Calculator
@@ -22,18 +23,18 @@ namespace Microsoft.Plugin.Calculator
                         @"[ei]|[0-9]|[\+\-\*\/\^\., ""]|[\(\)\|\!\[\]]" +
                         @")+$", RegexOptions.Compiled);
         private static readonly Regex RegBrackets = new Regex(@"[\(\)\[\]]", RegexOptions.Compiled);
-        private static readonly Engine MagesEngine;
+        private static readonly Engine MagesEngine = new Engine();
         private PluginInitContext Context { get; set; }
         private string IconPath { get; set; }
         private bool _disposed = false;
 
-        static Main()
-        {
-            MagesEngine = new Engine();
-        }
-
         public List<Result> Query(Query query)
         {
+            if(query == null)
+            {
+                throw new ArgumentNullException(paramName: nameof(query));
+            }
+
             if (query.Search.Length <= 2          // don't affect when user only input "e" or "i" keyword
                 || !RegValidExpressChar.IsMatch(query.Search)
                 || !IsBracketComplete(query.Search)) return new List<Result>();
@@ -88,10 +89,13 @@ namespace Microsoft.Plugin.Calculator
                         } 
                     };
                 }
-            }
-            catch
+            }
+//We want to keep the process alive if any the mages library throws any exceptions.
+#pragma warning disable CA1031 // Do not catch general exception types
+            catch(Exception e)
+#pragma warning restore CA1031 // Do not catch general exception types
             {
-                // ignored
+                Log.Exception($"|Microsoft.Plugin.Calculator.Main.Query|Exception when query for <{query}>", e);
             }
 
             return new List<Result>();
@@ -118,6 +122,11 @@ namespace Microsoft.Plugin.Calculator
 
         public void Init(PluginInitContext context)
         {
+            if(context == null)
+            {
+                throw new ArgumentNullException(paramName: nameof(context));
+            }
+
             Context = context;
             Context.API.ThemeChanged += OnThemeChanged;
             UpdateIconPath(Context.API.GetCurrentTheme());
diff --git a/src/modules/launcher/Plugins/Microsoft.Plugin.Calculator/Microsoft.Plugin.Calculator.csproj b/src/modules/launcher/Plugins/Microsoft.Plugin.Calculator/Microsoft.Plugin.Calculator.csproj
index 62e2a9cbf9..1ffec522fc 100644
--- a/src/modules/launcher/Plugins/Microsoft.Plugin.Calculator/Microsoft.Plugin.Calculator.csproj
+++ b/src/modules/launcher/Plugins/Microsoft.Plugin.Calculator/Microsoft.Plugin.Calculator.csproj
@@ -23,6 +23,7 @@
     <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
     <WarningLevel>4</WarningLevel>
     <Optimize>false</Optimize>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
@@ -97,7 +98,13 @@
   
   <ItemGroup>
     <PackageReference Include="JetBrains.Annotations" Version="2020.1.0" />
-    <PackageReference Include="Mages" Version="1.6.0" />
+    <PackageReference Include="Mages" Version="1.6.0" >
+      <NoWarn>NU1701</NoWarn>
+    </PackageReference>
+    <PackageReference Include="Microsoft.CodeAnalysis.FxCopAnalyzers" Version="2.9.6">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
     <PackageReference Include="System.Runtime" Version="4.3.1" />
   </ItemGroup>
   
diff --git a/src/modules/launcher/Plugins/Microsoft.Plugin.Calculator/NumberTranslator.cs b/src/modules/launcher/Plugins/Microsoft.Plugin.Calculator/NumberTranslator.cs
index c808eafb08..32b7cac5b8 100644
--- a/src/modules/launcher/Plugins/Microsoft.Plugin.Calculator/NumberTranslator.cs
+++ b/src/modules/launcher/Plugins/Microsoft.Plugin.Calculator/NumberTranslator.cs
@@ -36,6 +36,16 @@ namespace Microsoft.Plugin.Calculator
         /// <returns></returns>
         public static NumberTranslator Create(CultureInfo sourceCulture, CultureInfo targetCulture)
         {
+            if (sourceCulture == null)
+            {
+                throw new ArgumentNullException(paramName:nameof(sourceCulture));
+            }
+
+            if (targetCulture == null)
+            {
+                throw new ArgumentNullException(paramName: nameof(sourceCulture));
+            }
+
             bool conversionRequired = sourceCulture.NumberFormat.NumberDecimalSeparator != targetCulture.NumberFormat.NumberDecimalSeparator
                                       || sourceCulture.NumberFormat.PercentGroupSeparator != targetCulture.NumberFormat.PercentGroupSeparator
                                       || sourceCulture.NumberFormat.NumberGroupSizes != targetCulture.NumberFormat.NumberGroupSizes;
@@ -51,7 +61,7 @@ namespace Microsoft.Plugin.Calculator
         /// <returns></returns>
         public string Translate(string input)
         {
-            return this.Translate(input, this.sourceCulture, this.targetCulture, this.splitRegexForSource);
+            return Translate(input, this.sourceCulture, this.targetCulture, this.splitRegexForSource);
         }
         
         /// <summary>
@@ -61,10 +71,10 @@ namespace Microsoft.Plugin.Calculator
         /// <returns></returns>
         public string TranslateBack(string input)
         {
-            return this.Translate(input, this.targetCulture, this.sourceCulture, this.splitRegexForTarget);
+            return Translate(input, this.targetCulture, this.sourceCulture, this.splitRegexForTarget);
         }
 
-        private string Translate(string input, CultureInfo cultureFrom, CultureInfo cultureTo, Regex splitRegex)
+        private static string Translate(string input, CultureInfo cultureFrom, CultureInfo cultureTo, Regex splitRegex)
         {
             var outputBuilder = new StringBuilder();