Added additional dns error handling

Moonlight/App/Services/DomainService.cs

@@ -183,6 +183,8 @@ public class DomainService
         if (!ConfigService.Get().Moonlight.Domains.Enable)
             throw new DisplayException("This operation is disabled");
 
+        try
+        {
             var domain = EnsureData(d);
 
             var rname = $"{domain.Name}.{domain.SharedDomain.Name}";
@@ -236,6 +238,15 @@ public class DomainService
                     Name = name
                 }));
             }
+        }
+        catch (OverflowException)
+        {
+            throw new DisplayException("Invalid dns record values");
+        }
+        catch (FormatException)
+        {
+            throw new DisplayException("Invalid dns record values");
+        }
 
         //TODO: AuditLog
     }