Improved Unknown Assembly Experience/Messaging (#559)

src/ExtendedXmlSerializer/ReflectionModel/AssemblyLoader.cs

@@ -32,7 +32,7 @@ public Assembly Get(string parameter)
 				{
 					return Assembly.LoadFile(_path(parameter));
 				}
-				catch
+				catch (Exception error)
 				{
 					var length = _loaded.Length;
 					for (var i = 0; i < length; i++)
@@ -44,9 +44,7 @@ public Assembly Get(string parameter)
 						}
 					}
 
-#pragma warning disable CS0618
-					return Assembly.LoadWithPartialName(parameter);
-#pragma warning restore CS0618
+					throw new InvalidOperationException($"Could not load assembly '{parameter}'.  Are you sure it exists?", error);
 				}
 			}
 		}

test/ExtendedXmlSerializer.Tests.ReportedIssues/Issue558Tests.cs

@@ -0,0 +1,27 @@
+using ExtendedXmlSerializer.Configuration;
+using ExtendedXmlSerializer.Tests.ReportedIssues.Support;
+using FluentAssertions;
+using System;
+using Xunit;
+
+namespace ExtendedXmlSerializer.Tests.ReportedIssues
+{
+	public sealed class Issue558Tests
+	{
+		[Fact]
+		public void Verify()
+		{
+			var subject = new ConfigurationContainer().Create().ForTesting();
+
+			const string document =
+				@"<?xml version=""1.0"" encoding=""utf-8""?><Issue558Tests-Subject xmlns=""clr-namespace:ExtendedXmlSerializer.Tests.ReportedIssues;assembly=ExtendedXmlSerializer.Tests.ReportedIssues.DoesNotExist"" />";
+
+			subject.Invoking(x => x.Deserialize<Subject>(document))
+			       .Should()
+			       .ThrowExactly<InvalidOperationException>()
+			       .WithMessage("Could not load assembly 'ExtendedXmlSerializer.Tests.ReportedIssues.DoesNotExist'.  Are you sure it exists?");
+		}
+
+		sealed class Subject {}
+	}
+}