diff --git a/apps/server/AliasVault.Client/Services/EmailService.cs b/apps/server/AliasVault.Client/Services/EmailService.cs
index b50d5d898..2d66432ee 100644
--- a/apps/server/AliasVault.Client/Services/EmailService.cs
+++ b/apps/server/AliasVault.Client/Services/EmailService.cs
@@ -80,12 +80,12 @@ public sealed class EmailService(DbService dbService, JsInteropService jsInterop
 
             try
             {
-                var decryptedSymmetricKey = await jsInteropService.DecryptWithPrivateKey(email.EncryptedSymmetricKey, privateKey.PrivateKey);
-                email.Subject = await jsInteropService.SymmetricDecrypt(email.Subject, Convert.ToBase64String(decryptedSymmetricKey));
-                email.FromDisplay = await jsInteropService.SymmetricDecrypt(email.FromDisplay, Convert.ToBase64String(decryptedSymmetricKey));
-                email.FromLocal = await jsInteropService.SymmetricDecrypt(email.FromLocal, Convert.ToBase64String(decryptedSymmetricKey));
-                email.FromDomain = await jsInteropService.SymmetricDecrypt(email.FromDomain, Convert.ToBase64String(decryptedSymmetricKey));
-                email.MessagePreview = await jsInteropService.SymmetricDecrypt(email.MessagePreview, Convert.ToBase64String(decryptedSymmetricKey));
+                var decryptedSymmetricKeyBase64 = await jsInteropService.DecryptWithPrivateKey(email.EncryptedSymmetricKey, privateKey.PrivateKey);
+                email.Subject = await jsInteropService.SymmetricDecrypt(email.Subject, decryptedSymmetricKeyBase64);
+                email.FromDisplay = await jsInteropService.SymmetricDecrypt(email.FromDisplay, decryptedSymmetricKeyBase64);
+                email.FromLocal = await jsInteropService.SymmetricDecrypt(email.FromLocal, decryptedSymmetricKeyBase64);
+                email.FromDomain = await jsInteropService.SymmetricDecrypt(email.FromDomain, decryptedSymmetricKeyBase64);
+                email.MessagePreview = await jsInteropService.SymmetricDecrypt(email.MessagePreview, decryptedSymmetricKeyBase64);
             }
             catch (Exception ex)
             {
@@ -110,8 +110,8 @@ public sealed class EmailService(DbService dbService, JsInteropService jsInterop
 
         try
         {
-            var decryptedSymmetricKey = await jsInteropService.DecryptWithPrivateKey(email.EncryptedSymmetricKey, privateKey.PrivateKey);
-            var decryptedBase64 = await jsInteropService.SymmetricDecryptBytes(encryptedBytes, Convert.ToBase64String(decryptedSymmetricKey));
+            var decryptedSymmetricKeyBase64 = await jsInteropService.DecryptWithPrivateKey(email.EncryptedSymmetricKey, privateKey.PrivateKey);
+            var decryptedBase64 = await jsInteropService.SymmetricDecryptBytes(encryptedBytes, decryptedSymmetricKeyBase64);
             return decryptedBase64;
         }
         catch (Exception ex)
@@ -133,21 +133,21 @@ public sealed class EmailService(DbService dbService, JsInteropService jsInterop
 
         try
         {
-            var decryptedSymmetricKey = await jsInteropService.DecryptWithPrivateKey(email.EncryptedSymmetricKey, privateKey.PrivateKey);
-            email.Subject = await jsInteropService.SymmetricDecrypt(email.Subject, Convert.ToBase64String(decryptedSymmetricKey));
+            var decryptedSymmetricKeyBase64 = await jsInteropService.DecryptWithPrivateKey(email.EncryptedSymmetricKey, privateKey.PrivateKey);
+            email.Subject = await jsInteropService.SymmetricDecrypt(email.Subject, decryptedSymmetricKeyBase64);
             if (email.MessageHtml is not null)
             {
-                email.MessageHtml = await jsInteropService.SymmetricDecrypt(email.MessageHtml, Convert.ToBase64String(decryptedSymmetricKey));
+                email.MessageHtml = await jsInteropService.SymmetricDecrypt(email.MessageHtml, decryptedSymmetricKeyBase64);
             }
 
             if (email.MessagePlain is not null)
             {
-                email.MessagePlain = await jsInteropService.SymmetricDecrypt(email.MessagePlain, Convert.ToBase64String(decryptedSymmetricKey));
+                email.MessagePlain = await jsInteropService.SymmetricDecrypt(email.MessagePlain, decryptedSymmetricKeyBase64);
             }
 
-            email.FromDisplay = await jsInteropService.SymmetricDecrypt(email.FromDisplay, Convert.ToBase64String(decryptedSymmetricKey));
-            email.FromLocal = await jsInteropService.SymmetricDecrypt(email.FromLocal, Convert.ToBase64String(decryptedSymmetricKey));
-            email.FromDomain = await jsInteropService.SymmetricDecrypt(email.FromDomain, Convert.ToBase64String(decryptedSymmetricKey));
+            email.FromDisplay = await jsInteropService.SymmetricDecrypt(email.FromDisplay, decryptedSymmetricKeyBase64);
+            email.FromLocal = await jsInteropService.SymmetricDecrypt(email.FromLocal, decryptedSymmetricKeyBase64);
+            email.FromDomain = await jsInteropService.SymmetricDecrypt(email.FromDomain, decryptedSymmetricKeyBase64);
         }
         catch (Exception ex)
         {
diff --git a/apps/server/AliasVault.Client/Services/JsInterop/JsInteropService.cs b/apps/server/AliasVault.Client/Services/JsInterop/JsInteropService.cs
index 0f12323f3..4fc60280b 100644
--- a/apps/server/AliasVault.Client/Services/JsInterop/JsInteropService.cs
+++ b/apps/server/AliasVault.Client/Services/JsInterop/JsInteropService.cs
@@ -199,13 +199,13 @@ public sealed class JsInteropService(IJSRuntime jsRuntime)
     /// </summary>
     /// <param name="base64Ciphertext">Ciphertext to decrypt.</param>
     /// <param name="privateKey">Private key to use for decryption.</param>
-    /// <returns>Decrypted string.</returns>
-    public async Task<byte[]> DecryptWithPrivateKey(string base64Ciphertext, string privateKey)
+    /// <returns>Decrypted bytes as base64 string.</returns>
+    public async Task<string> DecryptWithPrivateKey(string base64Ciphertext, string privateKey)
     {
         try
         {
-            // Invoke the JavaScript function and get the result as a byte array
-            byte[] result = await jsRuntime.InvokeAsync<byte[]>("rsaInterop.decryptWithPrivateKey", base64Ciphertext, privateKey);
+            // Invoke the JavaScript function and get the result as a base64 string
+            string result = await jsRuntime.InvokeAsync<string>("rsaInterop.decryptWithPrivateKey", base64Ciphertext, privateKey);
             return result;
         }
         catch (JSException ex)
diff --git a/apps/server/AliasVault.Client/wwwroot/js/crypto.js b/apps/server/AliasVault.Client/wwwroot/js/crypto.js
index 7610ba8af..ecdd21190 100644
--- a/apps/server/AliasVault.Client/wwwroot/js/crypto.js
+++ b/apps/server/AliasVault.Client/wwwroot/js/crypto.js
@@ -28,7 +28,7 @@ function checkCryptoAvailable() {
 window.cryptoInterop = {
     encrypt: async function (plaintext, base64Key) {
         checkCryptoAvailable();
-        
+
         const key = await window.crypto.subtle.importKey(
             "raw",
             Uint8Array.from(atob(base64Key), c => c.charCodeAt(0)),
@@ -62,7 +62,7 @@ window.cryptoInterop = {
     },
     decrypt: async function (base64Ciphertext, base64Key) {
         checkCryptoAvailable();
-        
+
         const key = await window.crypto.subtle.importKey(
             "raw",
             Uint8Array.from(atob(base64Key), c => c.charCodeAt(0)),
@@ -89,7 +89,7 @@ window.cryptoInterop = {
     },
     decryptBytes: async function (base64Ciphertext, base64Key) {
         checkCryptoAvailable();
-        
+
         const key = await window.crypto.subtle.importKey(
             "raw",
             Uint8Array.from(atob(base64Key), c => c.charCodeAt(0)),
@@ -126,7 +126,7 @@ window.rsaInterop = {
      */
     generateRsaKeyPair : async function() {
         checkCryptoAvailable();
-        
+
         const keyPair = await window.crypto.subtle.generateKey(
             {
                 name: "RSA-OAEP",
@@ -154,7 +154,7 @@ window.rsaInterop = {
      */
     encryptWithPublicKey : async function(plaintext, publicKey) {
         checkCryptoAvailable();
-        
+
         const publicKeyObj = await window.crypto.subtle.importKey(
             "jwk",
             JSON.parse(publicKey),
@@ -181,11 +181,11 @@ window.rsaInterop = {
      * Decrypts a ciphertext string using an RSA private key.
      * @param {string} ciphertext - The base64-encoded ciphertext to decrypt.
      * @param {string} privateKey - The private key in JWK format.
-     * @returns {Promise<Uint8Array>} A promise that resolves to the decrypted data as a Uint8Array.
+     * @returns {Promise<string>} A promise that resolves to the decrypted data as a base64 string.
      */
     decryptWithPrivateKey: async function(ciphertext, privateKey) {
         checkCryptoAvailable();
-        
+
         try {
             // Parse the private key
             let parsedPrivateKey = JSON.parse(privateKey);
@@ -215,8 +215,9 @@ window.rsaInterop = {
                 cipherBuffer
             );
 
-            // Return the decrypted data as a Uint8Array
-            return new Uint8Array(plaintextBuffer);
+            // Convert to base64 string instead of returning Uint8Array to avoid Blazor serialization issues, see https://github.com/dotnet/aspnetcore/issues/59837
+            const decryptedBytes = new Uint8Array(plaintextBuffer);
+            return btoa(String.fromCharCode.apply(null, Array.from(decryptedBytes)));
         } catch (error) {
             throw new Error(`Failed to decrypt: ${error.message}`);
         }