Index: lams_admin/web/cleanupPreviewLessons.jsp
===================================================================
diff -u -rfba2480356aa5ddda0c8308eb917d72d16aa32eb -r4799cad19abde4669b7c14c40e36d56aec3a32fc
--- lams_admin/web/cleanupPreviewLessons.jsp	(.../cleanupPreviewLessons.jsp)	(revision fba2480356aa5ddda0c8308eb917d72d16aa32eb)
+++ lams_admin/web/cleanupPreviewLessons.jsp	(.../cleanupPreviewLessons.jsp)	(revision 4799cad19abde4669b7c14c40e36d56aec3a32fc)
@@ -18,54 +18,54 @@
 		}
 		
 		deleteButton.prop('disabled', true);
+		$('#deletingBox').show();
 		
-		var previewCountSpan = $('#previewCount'),
-			allLessonCountSpan = $('#allLessonCount'),
-			deletingBox = $('#deletingBox').show();
-		
 		// delete lesson in batches of 5 until done
-		while (previewCount > 0) {
-			$.ajax({
-				'async'   : false,
-				'cache'   : false,
-				'url'     : '<lams:WebAppURL />cleanupPreviewLessons.do',
-				'data'    : {
-					'method' : 'deletePreviewLessons',
-					'limit'  : 5
-				},
-				'success' : function(response){
-					try {
-						previewCount = response[0];
-						previewCountSpan.text(previewCount);
-						allLessonCountSpan.text(response[1]);
-					} catch(err) {
-						alert('<fmt:message key="msg.cleanup.preview.lesson.error" />');
-						previewCount = 0;
-					}
-				},
-				'error'	  : function(){
-					alert('<fmt:message key="msg.cleanup.preview.lesson.error" />');
-					previewCount = 0;
-				}
-			});
-		}
-		
-		deletingBox.hide();
-		if (previewCount > 0) {
-			deleteButton.prop('disabled', false);
-		}
+		deletePreviewLessons(previewCount, $('#previewCount'), $('#allLessonCount'));
 	});
 });
+
+function deletePreviewLessons(previewCount, previewCountSpan, allLessonCountSpan){
+	if (previewCount <= 0) {
+		$('#deletingBox').hide();
+		return;
+	}
+	$.ajax({
+		'cache'   : false,
+		'url'     : '<lams:WebAppURL />cleanupPreviewLessons.do',
+		'data'    : {
+			'method' : 'deletePreviewLessons',
+			'limit'  : 5
+		},
+		'success' : function(response){
+			try {
+				previewCount = response[0];
+				previewCountSpan.text(previewCount);
+				allLessonCountSpan.text(response[1]);
+				setTimeout(function(){
+					deletePreviewLessons(previewCount, previewCountSpan, allLessonCountSpan);
+				}, 500);
+			} catch(err) {
+				alert('<fmt:message key="msg.cleanup.preview.lesson.error" />');
+				previewCountSpan.text('ERROR');
+				allLessonCountSpan.text('ERROR');
+			}
+		},
+		'error'	  : function(){
+			alert('<fmt:message key="msg.cleanup.preview.lesson.error" />');
+		}
+	});
+}
 </script>
 
 <p><a href="<lams:LAMSURL/>admin/sysadminstart.do" class="btn btn-default"><fmt:message key="sysadmin.maintain" /></a></p>
 
 <html:errors />
 
 <fmt:message key="label.cleanup.preview.lesson.count" />&nbsp;<span id="previewCount">${previewCount}</span> / <span id="allLessonCount">${allLessonCount}</span>
-<p id="deletingBox" style="display: none;">
+<div id="deletingBox" style="display: none">
 	<fmt:message key="label.cleanup.preview.lesson.progress" />
-</p>
+</div>
 
 <div class="pull-right">
 	<button id="deleteButton" class="btn btn-primary loffset5"><fmt:message key="admin.delete"/></button>
Index: lams_common/src/java/org/lamsfoundation/lams/toolApplicationContext.xml
===================================================================
diff -u -rde884cf8c730a25d2f2296f7a768d3fd45508c99 -r4799cad19abde4669b7c14c40e36d56aec3a32fc
--- lams_common/src/java/org/lamsfoundation/lams/toolApplicationContext.xml	(.../toolApplicationContext.xml)	(revision de884cf8c730a25d2f2296f7a768d3fd45508c99)
+++ lams_common/src/java/org/lamsfoundation/lams/toolApplicationContext.xml	(.../toolApplicationContext.xml)	(revision 4799cad19abde4669b7c14c40e36d56aec3a32fc)
@@ -61,6 +61,7 @@
 			<props>
 				<prop key="createToolSession*">PROPAGATION_REQUIRED</prop>
 				<prop key="notifyTool*">PROPAGATION_REQUIRED</prop>
+				<prop key="notifyToolToDeleteContent">PROPAGATION_REQUIRES_NEW</prop>
 			    <prop key="update*">PROPAGATION_REQUIRED</prop>
 			    <prop key="remove*">PROPAGATION_REQUIRED</prop>
 			    <!-- It needs to be committed before the subsequent isReadOnly check -->
Index: lams_tool_daco/src/java/org/lamsfoundation/lams/tool/daco/dbupdates/patch20160927.sql
===================================================================
diff -u
--- lams_tool_daco/src/java/org/lamsfoundation/lams/tool/daco/dbupdates/patch20160927.sql	(revision 0)
+++ lams_tool_daco/src/java/org/lamsfoundation/lams/tool/daco/dbupdates/patch20160927.sql	(revision 4799cad19abde4669b7c14c40e36d56aec3a32fc)
@@ -0,0 +1,17 @@
+-- Turn off autocommit, so nothing is committed if there is an error
+SET AUTOCOMMIT = 0;
+SET FOREIGN_KEY_CHECKS=0;
+----------------------Put all sql statements below here-------------------------
+
+-- LDEV-3640 Add necessary cascades
+
+ALTER TABLE tl_ladaco10_users DROP FOREIGN KEY UserToDaco;
+ALTER TABLE tl_ladaco10_users ADD CONSTRAINT UserToDaco FOREIGN KEY (content_uid)
+REFERENCES tl_ladaco10_contents (uid) ON DELETE CASCADE ON UPDATE CASCADE;
+
+----------------------Put all sql statements above here-------------------------
+
+-- If there were no errors, commit and restore autocommit to on
+COMMIT;
+SET AUTOCOMMIT = 1;
+SET FOREIGN_KEY_CHECKS=1;
\ No newline at end of file
Index: lams_tool_spreadsheet/src/java/org/lamsfoundation/lams/tool/spreadsheet/service/SpreadsheetServiceImpl.java
===================================================================
diff -u -rce9f4e0c6d1e5814bf0dcb0fa16ae888a8c854a3 -r4799cad19abde4669b7c14c40e36d56aec3a32fc
--- lams_tool_spreadsheet/src/java/org/lamsfoundation/lams/tool/spreadsheet/service/SpreadsheetServiceImpl.java	(.../SpreadsheetServiceImpl.java)	(revision ce9f4e0c6d1e5814bf0dcb0fa16ae888a8c854a3)
+++ lams_tool_spreadsheet/src/java/org/lamsfoundation/lams/tool/spreadsheet/service/SpreadsheetServiceImpl.java	(.../SpreadsheetServiceImpl.java)	(revision 4799cad19abde4669b7c14c40e36d56aec3a32fc)
@@ -543,6 +543,7 @@
 	    for (SpreadsheetUser user : users) {
 		UserModifiedSpreadsheet modified = user.getUserModifiedSpreadsheet();
 		if (modified != null) {
+		    user.setUserModifiedSpreadsheet(null);
 		    userModifiedSpreadsheetDao.removeObject(UserModifiedSpreadsheet.class, modified.getUid());
 		}
 	    }
@@ -645,7 +646,7 @@
     public ToolOutput getToolOutput(String name, Long toolSessionId, Long learnerId) {
 	return null;
     }
-    
+
     @Override
     public List<ToolOutput> getToolOutputs(String name, Long toolContentId) {
 	return new ArrayList<ToolOutput>();