diff --git a/core/components/com_courses/admin/controllers/assets.php b/core/components/com_courses/admin/controllers/assets.php
index b37ea9f5a85..6466943c2e4 100644
--- a/core/components/com_courses/admin/controllers/assets.php
+++ b/core/components/com_courses/admin/controllers/assets.php
@@ -86,8 +86,17 @@ public function displayTask()
 		$tbl = new Tables\Asset($this->database);
 		// print_r($this->view->filters);
 
+		// A scope id of 0 here means "every scope", but the table now reads a
+		// zero as "match nothing", so drop the key instead of passing it.
+		$where = $this->view->filters;
+
+		if (empty($where['asset_scope_id']))
+		{
+			unset($where['asset_scope_id']);
+		}
+
 		$rows = $tbl->find(array(
-			'w' => $this->view->filters
+			'w' => $where
 		));
 
 		// print_r($rows);
diff --git a/core/components/com_courses/models/section.php b/core/components/com_courses/models/section.php
index 74dd518a2fd..2b4d6595f36 100644
--- a/core/components/com_courses/models/section.php
+++ b/core/components/com_courses/models/section.php
@@ -310,7 +310,7 @@ public function access($action='view', $item='section')
 		if (!isset($this->_permissions))
 		{
 			$this->_permissions = Permissions::getInstance();
-			$this->_permissions->set('offering_id', $this->get('id'));
+			$this->_permissions->set('offering_id', $this->get('offering_id'));
 			$this->_permissions->set('section_id', $this->get('id'));
 		}
 		return $this->_permissions->access($action, $item);
diff --git a/core/components/com_courses/tables/asset.group.php b/core/components/com_courses/tables/asset.group.php
index a85c71c2144..a7f79a8a3f5 100644
--- a/core/components/com_courses/tables/asset.group.php
+++ b/core/components/com_courses/tables/asset.group.php
@@ -101,7 +101,8 @@ private function _buildQuery($filters=array())
 
 		$where = array();
 
-		if (isset($filters['unit_id']) && $filters['unit_id'])
+		// A unit_id of 0 must match no groups rather than dropping the clause
+		if (isset($filters['unit_id']))
 		{
 			$where[] = "cag.unit_id=" . $this->_db->quote($filters['unit_id']);
 		}
diff --git a/core/components/com_courses/tables/asset.php b/core/components/com_courses/tables/asset.php
index fde041a88ce..cd247003a11 100644
--- a/core/components/com_courses/tables/asset.php
+++ b/core/components/com_courses/tables/asset.php
@@ -127,7 +127,8 @@ private function _buildQuery($filters=array())
 		{
 			$where[] = "ca.id=" . $this->_db->quote((int) $filters['asset_id']);
 		}
-		if (!empty($filters['asset_scope_id']))
+		// A scope id of 0 must match no assets rather than dropping the clause
+		if (isset($filters['asset_scope_id']))
 		{
 			$where[] = "cag.id=" . $this->_db->quote((int) $filters['asset_scope_id']);
 		}
diff --git a/core/components/com_courses/tables/unit.php b/core/components/com_courses/tables/unit.php
index 8e252801699..17022b0edbc 100644
--- a/core/components/com_courses/tables/unit.php
+++ b/core/components/com_courses/tables/unit.php
@@ -128,7 +128,9 @@ private function _buildQuery($filters=array())
 
 		$where = array();
 
-		if (isset($filters['offering_id']) && $filters['offering_id'])
+		// Note the deliberate lack of a truthiness test: an offering_id of 0
+		// has to match no units, not every unit in the table.
+		if (isset($filters['offering_id']))
 		{
 			$where[] = "cu.offering_id=" . $this->_db->quote($filters['offering_id']);
 		}
diff --git a/core/plugins/courses/outline/views/outline/tmpl/edittool.php b/core/plugins/courses/outline/views/outline/tmpl/edittool.php
index 9f39b14e7f0..6ab9f3c72f1 100644
--- a/core/plugins/courses/outline/views/outline/tmpl/edittool.php
+++ b/core/plugins/courses/outline/views/outline/tmpl/edittool.php
@@ -86,7 +86,7 @@
 			</div>
 		</div>
 		<div class="tool-files-available">
-			<?php $files = $toolAsset ? $toolAsset->files($asset) : array(); ?>
+			<?php $files = ($toolAsset && method_exists($toolAsset, 'files')) ? $toolAsset->files($asset) : array(); ?>
 			<?php if (!empty($files)) : ?>
 				<ul class="tool-files-list">
 					<?php foreach ($files as $file) : ?>