diff --git a/Data/Extensions.cs b/Data/Extensions.cs
index 3aa3e36..2b6fe1d 100644
--- a/Data/Extensions.cs
+++ b/Data/Extensions.cs
@@ -1053,7 +1053,7 @@ namespace SabreTools.RedumpLib.Data
 
             foreach (var val in Enum.GetValues(typeof(MediaType)))
             {
-                if (((MediaType)val) == MediaType.NONE)
+                if (val == null || ((MediaType)val) == MediaType.NONE)
                     continue;
 
                 mediaTypes.Add($"{((MediaType?)val).ShortName()} - {((MediaType?)val).LongName()}");
diff --git a/SabreTools.RedumpLib.csproj b/SabreTools.RedumpLib.csproj
index 7bed56b..5e2a9d4 100644
--- a/SabreTools.RedumpLib.csproj
+++ b/SabreTools.RedumpLib.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <!-- Assembly Properties -->
-    <TargetFrameworks>net48;net6.0;net7.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net40;net452;net462;net472;net48;netcoreapp3.1;net5.0;net6.0;net7.0;net8.0</TargetFrameworks>
     <RuntimeIdentifiers>win-x86;win-x64;win-arm64;linux-x64;linux-arm64;osx-x64;osx-arm64</RuntimeIdentifiers>
     <LangVersion>latest</LangVersion>
     <Nullable>enable</Nullable>
@@ -25,6 +25,11 @@
     <None Include="README.md" Pack="true" PackagePath=""/>
   </ItemGroup>
 
+  <!-- Support for old .NET versions -->
+  <ItemGroup Condition="$(TargetFramework.StartsWith(`net4`))">
+    <PackageReference Include="System.ValueTuple" Version="4.5.0" />
+  </ItemGroup>
+
   <ItemGroup>
     <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
   </ItemGroup>
diff --git a/Web/RedumpHttpClient.cs b/Web/RedumpHttpClient.cs
index 3343893..7968624 100644
--- a/Web/RedumpHttpClient.cs
+++ b/Web/RedumpHttpClient.cs
@@ -170,8 +170,11 @@ namespace SabreTools.RedumpLib.Web
 
             // Otherwise, traverse each dump on the page
             var matches = Constants.DiscRegex.Matches(dumpsPage);
-            foreach (Match match in matches)
+            foreach (Match? match in matches)
             {
+                if (match == null)
+                    continue;
+
                 try
                 {
                     if (int.TryParse(match.Groups[1].Value, out int value))
@@ -219,8 +222,11 @@ namespace SabreTools.RedumpLib.Web
 
             // Otherwise, traverse each dump on the page
             var matches = Constants.DiscRegex.Matches(dumpsPage);
-            foreach (Match match in matches)
+            foreach (Match? match in matches)
             {
+                if (match == null)
+                    continue;
+
                 try
                 {
                     if (int.TryParse(match.Groups[1].Value, out int value))
@@ -258,8 +264,11 @@ namespace SabreTools.RedumpLib.Web
 
             // Otherwise, traverse each dump on the page
             var matches = Constants.NewDiscRegex.Matches(dumpsPage);
-            foreach (Match match in matches)
+            foreach (Match? match in matches)
             {
+                if (match == null)
+                    continue;
+
                 try
                 {
                     if (int.TryParse(match.Groups[2].Value, out int value))
@@ -293,8 +302,11 @@ namespace SabreTools.RedumpLib.Web
 
             // Otherwise, traverse each dump on the page
             var matches = Constants.NewDiscRegex.Matches(dumpsPage);
-            foreach (Match match in matches)
+            foreach (Match? match in matches)
             {
+                if (match == null)
+                    continue;
+
                 try
                 {
                     if (int.TryParse(match.Groups[2].Value, out int value))
diff --git a/Web/RedumpWebClient.cs b/Web/RedumpWebClient.cs
index 9c99e2b..45b51fd 100644
--- a/Web/RedumpWebClient.cs
+++ b/Web/RedumpWebClient.cs
@@ -101,7 +101,11 @@ namespace SabreTools.RedumpLib.Web
             }
 
             // HTTP encode the password
+#if NET40
+            password = Uri.EscapeUriString(password);
+#else
             password = WebUtility.UrlEncode(password);
+#endif
 
             // Attempt to login up to 3 times
             for (int i = 0; i < 3; i++)