That's very strange. Can you post the full logs? I want to make sure those aren't misleading errors caused by a previous error.
Level: INFO
When: 2015-02-03 15:33:01
From: stencyl.sw.util.StreamGobbler
/Users/dariolessa/stencylworks/engine-extensions/chartboost/MyChartboost.hx:8: characters 7-17 : Class not found : openfl.Lib
Level: INFO
When: 2015-02-03 15:33:01
From: stencyl.sw.util.StreamGobbler
Source/scripts/ActorEvents_110.hx:70: lines 70-100 : Defined in this class
Level: INFO
When: 2015-02-03 15:33:01
From: stencyl.sw.util.StreamGobbler
Source/scripts/ActorEvents_110.hx:89: characters 8-38 : #MyChartboost has no field cacheInterstitial
Level: ERROR
When: 2015-02-03 15:33:01
From: stencyl.sw.io.write.resource.HXWriter
Events for 'play': #MyChartboost has no field cacheInterstitial
from scripts.ActorEvents_110
line: 89
columns: 8-38
Level: INFO
When: 2015-02-03 15:33:01
From: stencyl.sw.util.StreamGobbler
Source/scripts/ActorEvents_110.hx:90: characters 8-37 : #MyChartboost has no field showInterstitial
Level: ERROR
When: 2015-02-03 15:33:01
From: stencyl.sw.io.write.resource.HXWriter
Events for 'play': #MyChartboost has no field showInterstitial
from scripts.ActorEvents_110
line: 90
columns: 8-37