diff --git a/ucs-school-umc-computerroom/umc/python/computerroom/__init__.py b/ucs-school-umc-computerroom/umc/python/computerroom/__init__.py
index 943bba6..312400e 100644
--- a/ucs-school-umc-computerroom/umc/python/computerroom/__init__.py
+++ b/ucs-school-umc-computerroom/umc/python/computerroom/__init__.py
@@ -361,8 +361,11 @@ class Instance(SchoolBaseModule):
 	def rooms(self, request, ldap_user_read=None):
 		"""Returns a list of all available rooms"""
 		rooms = []
-		# create search base for current school
-		for room in ComputerRoom.get_all(ldap_user_read, request.options['school']):
+		try:
+			all_rooms = ComputerRoom.get_all(ldap_user_read, request.options['school'])
+		except noObject:
+			all_rooms = []
+		for room in all_rooms:
 			room_info = _readRoomInfo(room.dn) or dict()
 			user_dn = room_info.get('user')
 			locked = user_dn and user_dn != self._user_dn and ('pid' in room_info or 'exam' in room_info)