Corrections as recommended.

Emby.Server.Implementations/Updates/InstallationManager.cs

@@ -92,7 +92,7 @@ namespace Emby.Server.Implementations.Updates
             _httpClientFactory = httpClientFactory;
             _config = config;
             _zipClient = zipClient;
-            _jsonSerializerOptions = JsonDefaults.GetCamelCaseOptions();
+            _jsonSerializerOptions = JsonDefaults.GetOptions();
             _pluginManager = pluginManager;
         }
 
@@ -104,8 +104,7 @@ namespace Emby.Server.Implementations.Updates
         {
             try
             {
-                List<PackageInfo>? packages;
-                packages = await _httpClientFactory.CreateClient(NamedClient.Default)
+                List<PackageInfo>? packages = await _httpClientFactory.CreateClient(NamedClient.Default)
                         .GetFromJsonAsync<List<PackageInfo>>(new Uri(manifest), _jsonSerializerOptions, cancellationToken).ConfigureAwait(false);
 
                 if (packages == null)

Jellyfin.Api/Controllers/PluginsController.cs

@@ -217,8 +217,13 @@ namespace Jellyfin.Api.Controllers
                 plugin = plugins.OrderBy(p => p.Manifest.Status).FirstOrDefault();
             }
 
-            _installationManager.UninstallPlugin(plugin!);
-            return NoContent();
+            if (plugin != null)
+            {
+                _installationManager.UninstallPlugin(plugin!);
+                return NoContent();
+            }
+
+            return NotFound();
         }
 
         /// <summary>
@@ -303,10 +308,7 @@ namespace Jellyfin.Api.Controllers
                 || plugin.Manifest.ImageUrl == null
                 || !System.IO.File.Exists(imgPath))
             {
-                // Use a blank image.
-                var type = GetType();
-                var stream = type.Assembly.GetManifestResourceStream(type.Namespace + ".Plugins.blank.png");
-                return File(stream, "image/png");
+                return NotFound();
             }
 
             imgPath = Path.Combine(plugin.Path, plugin.Manifest.ImageUrl);
@@ -333,7 +335,7 @@ namespace Jellyfin.Api.Controllers
 
             if (plugin != null)
             {
-                return Ok(plugin.Manifest);
+                return plugin.Manifest;
             }
 
             return NotFound();