LevelHelper errors in Corona SDK

LevelHelper errors in Corona SDK

Yesterday I have started to make a game on Corona SDK with help of Level
Helper and Sprite Helper. I have used a video tutorial
(http://youtu.be/MHrhrg2Qi7M) and all things have been done exactly like
in video, but I have this error. I don't understand why?! File: ...DK
Projects/Runner/LevelHelper/LevelHelperLoader.lua Line: 743
stack traceback: [C]: ? ...DK
Projects/Runner/LevelHelper/LevelHelperLoader.lua:743: in function
'createAllNodes' ...DK
Projects/Runner/LevelHelper/LevelHelperLoader.lua:150: in function
'instantiateObjects' ...slav/Documents/Corona SDK
Projects/Runner/level1.lua:34: in function <...slav/Documents/Corona SDK
Projects/Runner/level1.lua:29> ?: in function 'dispatchEvent' ?: in
function 'gotoScene' ...heslav/Documents/Corona SDK
Projects/Runner/menu.lua:22: in function '_onRelease' ?: in function '?'
?: in function ?: in function
Attempt to index field 'lhNodes' (a nil value)
Can you please tell me , what I've done incorrectly. Thank you !
P.S. Sorry for my English ;)