diff --git a/API/Extensions/ClaimsPrincipalExtensions.cs b/API/Extensions/ClaimsPrincipalExtensions.cs
index 3dacfc854..61ece5676 100644
--- a/API/Extensions/ClaimsPrincipalExtensions.cs
+++ b/API/Extensions/ClaimsPrincipalExtensions.cs
@@ -1,4 +1,5 @@
 using System.Security.Claims;
+using Kavita.Common;
 
 namespace API.Extensions
 {
@@ -6,7 +7,9 @@ namespace API.Extensions
     {
         public static string GetUsername(this ClaimsPrincipal user)
         {
-            return user.FindFirst(ClaimTypes.NameIdentifier)?.Value;
+            var userClaim = user.FindFirst(ClaimTypes.NameIdentifier);
+            if (userClaim == null) throw new KavitaException("User is not authenticated");
+            return userClaim.Value;
         }
     }
 }
\ No newline at end of file
diff --git a/API/Program.cs b/API/Program.cs
index 3bee9e202..4ea8f4e40 100644
--- a/API/Program.cs
+++ b/API/Program.cs
@@ -99,6 +99,7 @@ namespace API
                         options.AddExceptionFilterForType<OutOfMemoryException>();
                         options.AddExceptionFilterForType<NetVips.VipsException>();
                         options.AddExceptionFilterForType<InvalidDataException>();
+                        options.AddExceptionFilterForType<KavitaException>();
                         
                         options.BeforeSend = sentryEvent =>
                         {
diff --git a/Kavita.Common/KavitaException.cs b/Kavita.Common/KavitaException.cs
new file mode 100644
index 000000000..e91525f7e
--- /dev/null
+++ b/Kavita.Common/KavitaException.cs
@@ -0,0 +1,21 @@
+using System;
+
+namespace Kavita.Common
+{
+    /// <summary>
+    /// These are used for errors to send to the UI that should not be reported to Sentry
+    /// </summary>
+    [Serializable]
+    public class KavitaException : Exception
+    {
+        public KavitaException()
+        {
+
+        }
+
+        public KavitaException(string message) : base(message)
+        {
+
+        }
+    }
+}
\ No newline at end of file
diff --git a/README.md b/README.md
index 6e938811c..48f975d55 100644
--- a/README.md
+++ b/README.md
@@ -40,6 +40,7 @@ your reading collection with your friends and family!
 ## How to install
 - Unzip the archive for your target OS
 - Place in a directory that is writable. If on windows, do not place in Program Files
+- Linux users must ensure the directory & kavita.db is writable by Kavita (might require starting server once) 
 - Run Kavita
 - If you are updating, do not copy appsettings.json from the new version over. It will override your TokenKey and you will have to reauthenticate on your devices.