diff --git a/src/Database/Relations/AttachMany.php b/src/Database/Relations/AttachMany.php
index e57465d1b..36172083e 100644
--- a/src/Database/Relations/AttachMany.php
+++ b/src/Database/Relations/AttachMany.php
@@ -39,6 +39,18 @@ public function __construct(Builder $query, Model $parent, $type, $id, $isPublic
      */
     public function setSimpleValue($value)
     {
+        // Nulling the relationship
+        if (!$value) {
+            $this->parent->unsetRelation($this->relationName);
+
+            if ($this->parent->exists) {
+                $this->parent->bindEventOnce('model.afterSave', function() {
+                    $this->ensureRelationIsEmpty();
+                });
+            }
+            return;
+        }
+
         // Append a single newly uploaded file(s)
         if ($value instanceof UploadedFile) {
             $this->parent->bindEventOnce('model.afterSave', function () use ($value) {
diff --git a/src/Database/Relations/AttachOne.php b/src/Database/Relations/AttachOne.php
index f7e2a65a7..52d7c386b 100644
--- a/src/Database/Relations/AttachOne.php
+++ b/src/Database/Relations/AttachOne.php
@@ -43,6 +43,18 @@ public function setSimpleValue($value)
             $value = reset($value);
         }
 
+        // Nulling the relationship
+        if (!$value) {
+            $this->parent->setRelation($this->relationName, null);
+
+            if ($this->parent->exists) {
+                $this->parent->bindEventOnce('model.afterSave', function() {
+                    $this->ensureRelationIsEmpty();
+                });
+            }
+            return;
+        }
+
         // Newly uploaded file
         if ($value instanceof UploadedFile) {
             $this->parent->bindEventOnce('model.afterSave', function () use ($value) {
@@ -67,6 +79,10 @@ public function setSimpleValue($value)
 
         // The relation is set here to satisfy validation
         $this->parent->setRelation($this->relationName, $value);
+
+        $this->parent->bindEventOnce('model.afterValidate', function() {
+            $this->parent->unsetRelation($this->relationName);
+        });
     }
 
     /**
diff --git a/src/Database/Relations/AttachOneOrMany.php b/src/Database/Relations/AttachOneOrMany.php
index 6901ea613..e6f0ad40f 100644
--- a/src/Database/Relations/AttachOneOrMany.php
+++ b/src/Database/Relations/AttachOneOrMany.php
@@ -404,6 +404,21 @@ public function makeValidationFile($value)
         return $value;
     }
 
+    /**
+     * ensureRelationIsEmpty ensures the relation is empty, either deleted or nulled.
+     */
+    protected function ensureRelationIsEmpty()
+    {
+        $options = $this->parent->getRelationDefinition($this->relationName);
+
+        if (array_get($options, 'delete', false)) {
+            $this->delete();
+        }
+        else {
+            $this->update([$this->getForeignKeyName() => null]);
+        }
+    }
+
     /**
      * getRelatedKeyName
      * @return string
diff --git a/src/Database/Relations/HasMany.php b/src/Database/Relations/HasMany.php
index d10f9e969..27c74b7bd 100644
--- a/src/Database/Relations/HasMany.php
+++ b/src/Database/Relations/HasMany.php
@@ -37,6 +37,8 @@ public function setSimpleValue($value)
     {
         // Nulling the relationship
         if (!$value) {
+            $this->parent->unsetRelation($this->relationName);
+
             if ($this->parent->exists) {
                 $this->parent->bindEventOnce('model.afterSave', function() {
                     $this->ensureRelationIsEmpty();
diff --git a/src/Database/Relations/HasOne.php b/src/Database/Relations/HasOne.php
index 57db078c6..65c333760 100644
--- a/src/Database/Relations/HasOne.php
+++ b/src/Database/Relations/HasOne.php
@@ -39,6 +39,8 @@ public function setSimpleValue($value)
 
         // Nulling the relationship
         if (!$value) {
+            $this->parent->setRelation($this->relationName, null);
+
             if ($this->parent->exists) {
                 $this->parent->bindEventOnce('model.afterSave', function() {
                     $this->ensureRelationIsEmpty();
diff --git a/src/Database/Scopes/MultisiteScope.php b/src/Database/Scopes/MultisiteScope.php
index 7efe089f6..97dc394fe 100644
--- a/src/Database/Scopes/MultisiteScope.php
+++ b/src/Database/Scopes/MultisiteScope.php
@@ -16,7 +16,7 @@ class MultisiteScope implements ScopeInterface
     /**
      * @var array extensions to be added to the builder.
      */
-    protected $extensions = ['WithSite', 'WithSites'];
+    protected $extensions = ['WithSite', 'WithSites', 'WithSyncSites'];
 
     /**
      * apply the scope to a given Eloquent query builder.
@@ -29,12 +29,15 @@ public function apply(BuilderBase $builder, ModelBase $model)
     }
 
     /**
-     * addWithSite
+     * addWithSite removes this scope and includes the specified site
      */
     protected function addWithSite(BuilderBase $builder)
     {
         $builder->macro('withSite', function (BuilderBase $builder, $siteId) {
-            return $builder->where($builder->getModel()->getQualifiedSiteIdColumn(), $siteId);
+            return $builder
+                ->withoutGlobalScope($this)
+                ->where($builder->getModel()->getQualifiedSiteIdColumn(), $siteId)
+            ;
         });
     }
 
@@ -43,8 +46,25 @@ protected function addWithSite(BuilderBase $builder)
      */
     protected function addWithSites(BuilderBase $builder)
     {
-        $builder->macro('withSites', function (BuilderBase $builder) {
-            return $builder->withoutGlobalScope($this);
+        $builder->macro('withSites', function (BuilderBase $builder, $siteIds = null) {
+            if (!is_array($siteIds)) {
+                return $builder->withoutGlobalScope($this);
+            }
+
+            return $builder
+                ->withoutGlobalScope($this)
+                ->whereIn($builder->getModel()->getQualifiedSiteIdColumn(), $siteIds)
+            ;
+        });
+    }
+
+    /**
+     * addWithSyncSites removes this scope and includes sites that should be synced with this model
+     */
+    protected function addWithSyncSites(BuilderBase $builder)
+    {
+        $builder->macro('withSyncSites', function (BuilderBase $builder) {
+            return $builder->withSites($builder->getModel()->getMultisiteSyncSites());
         });
     }
 
diff --git a/src/Database/Traits/Multisite.php b/src/Database/Traits/Multisite.php
index 4a2b3bc24..7cc49a349 100644
--- a/src/Database/Traits/Multisite.php
+++ b/src/Database/Traits/Multisite.php
@@ -90,18 +90,20 @@ public function multisiteSaveComplete()
 
         Site::withGlobalContext(function() {
             $otherModels = $this->newOtherSiteQuery()->get();
-            $otherSites = $otherModels->pluck('site_id')->all();
+            $otherSites = $this->getMultisiteSyncSites();
 
             // Propagate attributes to known records
             if ($this->propagatable) {
-                foreach ($otherModels as $model) {
-                    $this->propagateToSite($model->site_id, $model);
+                foreach ($otherSites as $siteId) {
+                    if ($model = $otherModels->where('site_id', $siteId)->first()) {
+                        $this->propagateToSite($siteId, $model);
+                    }
                 }
             }
 
             // Sync non-existent records
             if ($this->isMultisiteSyncEnabled()) {
-                $missingSites = array_diff($this->getMultisiteSyncSites(), $otherSites);
+                $missingSites = array_diff($otherSites, $otherModels->pluck('site_id')->all());
                 foreach ($missingSites as $missingSite) {
                     $this->propagateToSite($missingSite);
                 }
@@ -280,6 +282,18 @@ public function propagateToSite($siteId, $otherModel = null)
         return $otherModel;
     }
 
+    /**
+     * getMultisiteKey returns the root key if multisite is used
+     */
+    public function getMultisiteKey()
+    {
+        if (!$this->isMultisiteEnabled()) {
+            return $this->getKey();
+        }
+
+        return $this->site_root_id ?: $this->getKey();
+    }
+
     /**
      * isMultisiteEnabled allows for programmatic toggling
      * @return bool
@@ -385,7 +399,7 @@ public function findOrCreateForSite($siteId = null)
 
         // Newly created model
         if (!$otherModel->exists) {
-            $otherModel->save();
+            $otherModel->save(['force' => true]);
         }
 
         // Restoring a trashed model
diff --git a/src/Extension/ExtendableTrait.php b/src/Extension/ExtendableTrait.php
index 45f292765..7780b9a69 100644
--- a/src/Extension/ExtendableTrait.php
+++ b/src/Extension/ExtendableTrait.php
@@ -45,7 +45,7 @@ trait ExtendableTrait
     public function extendableConstruct()
     {
         // Apply init callbacks
-        $classes = array_merge([static::class], class_parents($this));
+        $classes = array_merge([static::class], class_parents(static::class));
         foreach ($classes as $class) {
             if (isset(Container::$classCallbacks[$class]) && is_array(Container::$classCallbacks[$class])) {
                 foreach (Container::$classCallbacks[$class] as $callback) {
@@ -435,7 +435,7 @@ public function extendableGet($name)
             }
         }
 
-        $parent = get_parent_class();
+        $parent = get_parent_class(self::class);
         if ($parent !== false && method_exists($parent, '__get')) {
             return parent::__get($name);
         }
@@ -468,7 +468,7 @@ public function extendableSet($name, $value)
         }
 
         // This targets trait usage in particular
-        $parent = get_parent_class();
+        $parent = get_parent_class(self::class);
         if ($parent !== false && method_exists($parent, '__set')) {
             parent::__set($name, $value);
             $found = true;
@@ -504,7 +504,7 @@ public function extendableCall($name, $params = null)
             return call_user_func_array($callable, $params);
         }
 
-        $parent = get_parent_class();
+        $parent = get_parent_class(self::class);
         if ($parent !== false && method_exists($parent, '__call')) {
             return parent::__call($name, $params);
         }
diff --git a/src/Filesystem/Filesystem.php b/src/Filesystem/Filesystem.php
index 58021938a..f94d8160c 100644
--- a/src/Filesystem/Filesystem.php
+++ b/src/Filesystem/Filesystem.php
@@ -1,5 +1,6 @@
 <?php namespace October\Rain\Filesystem;
 
+use Event;
 use ReflectionClass;
 use FilesystemIterator;
 use Illuminate\Filesystem\Filesystem as FilesystemBase;
@@ -103,6 +104,20 @@ public function sizeToString($bytes)
      */
     public function localToPublic($path)
     {
+        /**
+         * @event filesystem.localToPublic
+         * Allow custom logic for converting local to public paths on non-standard installations.
+         *
+         * Example usage
+         *
+         *     Event::listen('filesystem.localToPublic', function ($path) {
+         *         return '/custom/public/path';
+         *     });
+         */
+        if (($event = Event::fire('filesystem.localToPublic', [$path], true)) !== null) {
+            return $event;
+        }
+        
         // Check real paths
         $basePath = base_path();
         if (strpos($path, $basePath) === 0) {
diff --git a/src/Foundation/Http/Kernel.php b/src/Foundation/Http/Kernel.php
index ecf03c536..b364ed777 100644
--- a/src/Foundation/Http/Kernel.php
+++ b/src/Foundation/Http/Kernel.php
@@ -41,10 +41,10 @@ class Kernel extends HttpKernel
      * @var array
      */
     protected $routeMiddleware = [
-        // 'auth' => \Illuminate\Auth\Middleware\Authenticate::class,
-        // 'auth.basic' => \Illuminate\Auth\Middleware\AuthenticateWithBasicAuth::class,
+        'auth' => \Illuminate\Auth\Middleware\Authenticate::class,
+        'auth.basic' => \Illuminate\Auth\Middleware\AuthenticateWithBasicAuth::class,
         'bindings' => \Illuminate\Routing\Middleware\SubstituteBindings::class,
-        // 'can' => \Illuminate\Auth\Middleware\Authorize::class,
+        'can' => \Illuminate\Auth\Middleware\Authorize::class,
         // 'guest' => \App\Http\Middleware\RedirectIfAuthenticated::class,
         'throttle' => \Illuminate\Routing\Middleware\ThrottleRequests::class,
     ];
@@ -79,9 +79,9 @@ class Kernel extends HttpKernel
     protected $middlewarePriority = [
         \Illuminate\Session\Middleware\StartSession::class,
         \Illuminate\View\Middleware\ShareErrorsFromSession::class,
-        // \Illuminate\Auth\Middleware\Authenticate::class,
-        // \Illuminate\Session\Middleware\AuthenticateSession::class,
+        \Illuminate\Auth\Middleware\Authenticate::class,
+        \Illuminate\Session\Middleware\AuthenticateSession::class,
         \Illuminate\Routing\Middleware\SubstituteBindings::class,
-        // \Illuminate\Auth\Middleware\Authorize::class,
+        \Illuminate\Auth\Middleware\Authorize::class,
     ];
 }
diff --git a/src/Html/Helper.php b/src/Html/Helper.php
index d1912b5dc..0b4f3eadd 100644
--- a/src/Html/Helper.php
+++ b/src/Html/Helper.php
@@ -17,7 +17,7 @@ class Helper
      */
     public static function nameToId($string)
     {
-        return rtrim(str_replace('--', '-', str_replace(['[', ']'], '-', $string)), '-');
+        return rtrim(str_replace('--', '-', str_replace(['[', ']', ':', '.'], '-', $string)), '-');
     }
 
     /**
diff --git a/src/Support/ClassLoader.php b/src/Support/ClassLoader.php
index 1a7673813..f46a98aa4 100644
--- a/src/Support/ClassLoader.php
+++ b/src/Support/ClassLoader.php
@@ -33,6 +33,11 @@ class ClassLoader
      */
     public $manifest = [];
 
+    /**
+     * @var array unknownClasses cache
+     */
+    protected $unknownClasses = [];
+
     /**
      * @var bool manifestDirty if manifest needs to be written
      */
@@ -68,6 +73,10 @@ public function __construct(Filesystem $files, string $basePath)
      */
     public function load($class): bool
     {
+        if (!str_contains($class, '\\')) {
+            return false;
+        }
+
         if (
             isset($this->manifest[$class]) &&
             is_file($fullPath = $this->basePath.DIRECTORY_SEPARATOR.$this->manifest[$class])
@@ -76,6 +85,10 @@ public function load($class): bool
             return true;
         }
 
+        if (isset($this->unknownClasses[$class])) {
+            return false;
+        }
+
         [$lowerClass, $upperClass] = $this->normalizeClass($class);
 
         // Load namespaces
@@ -94,6 +107,8 @@ public function load($class): bool
             }
         }
 
+        $this->unknownClasses[$class] = true;
+
         return false;
     }
 
@@ -150,7 +165,7 @@ public function register(): void
 
         $this->registered = spl_autoload_register(function($class) {
             $this->load($class);
-        }, true, true);
+        });
     }
 
     /**
diff --git a/src/Support/Facades/Site.php b/src/Support/Facades/Site.php
index 76736a686..4b7dc575b 100644
--- a/src/Support/Facades/Site.php
+++ b/src/Support/Facades/Site.php
@@ -13,9 +13,11 @@
  * @method static bool hasAnySite()
  * @method static bool hasMultiSite()
  * @method static bool hasSiteGroups()
- * @method static array listEnabled()
+ * @method static \System\Classes\SiteCollection listEnabled()
+ * @method static \System\Classes\SiteCollection listSites()
  * @method static array listSiteIds()
- * @method static iterable listSites()
+ * @method static array listSiteIdsInGroup($siteId)
+ * @method static array listSiteIdsInLocale($siteId)
  * @method static mixed getEditSite()
  * @method static string getEditSiteId()
  * @method static void setEditSiteId(string $siteId)
@@ -23,15 +25,13 @@
  * @method static mixed getAnyEditSite()
  * @method static bool hasAnyEditSite()
  * @method static bool hasMultiEditSite()
- * @method static iterable listEditEnabled()
+ * @method static \System\Classes\SiteCollection listEditEnabled()
  * @method static void applyEditSite(mixed $site)
  * @method static mixed getActiveSite()
  * @method static string getActiveSiteId()
  * @method static void setActiveSiteId(string $siteId)
  * @method static void setActiveSite(mixed $site)
  * @method static void applyActiveSite(mixed $site)
- * @method static array listSiteIdsInGroup($siteId)
- * @method static array listSiteIdsInLocale($siteId)
  * @method static int|null getSiteIdFromContext()
  * @method static string|null getSiteCodeFromContext()
  * @method static mixed getSiteFromContext()