Return NotFound when itemId isn't found

1 files changed, 5 insertions, 0 deletions

diff --git a/Jellyfin.Server.Implementations/Devices/DeviceManager.cs b/Jellyfin.Server.Implementations/Devices/DeviceManager.cs
index 8b15d6823..a4b4c1959 100644
--- a/Jellyfin.Server.Implementations/Devices/DeviceManager.cs
+++ b/Jellyfin.Server.Implementations/Devices/DeviceManager.cs
@@ -9,6 +9,7 @@ using Jellyfin.Data.Enums;
 using Jellyfin.Data.Events;
 using Jellyfin.Data.Queries;
 using Jellyfin.Extensions;
+using MediaBrowser.Common.Extensions;
 using MediaBrowser.Controller.Devices;
 using MediaBrowser.Controller.Library;
 using MediaBrowser.Model.Devices;
@@ -185,6 +186,10 @@ namespace Jellyfin.Server.Implementations.Devices
                 if (userId.HasValue)
                 {
                     var user = _userManager.GetUserById(userId.Value);
+                    if (user is null)
+                    {
+                        throw new ResourceNotFoundException();
+                    }
 
                     sessions = sessions.Where(i => CanAccessDevice(user, i.DeviceId));
                 }