let’s try to get into the issue a little bit:
1. Is the Chartboost import version matching the version you’ve actually installed (there is an update to version 1.1 available since the beginning of the week)? The latest plugin uses the import
import VPlay.plugins.chartboost 1.1
like in this demo file: https://github.com/vplayplugins/ChartboostSample/blob/master/main.qml
2. Also, if you’re using Android, could you please make sure that you added the following line in your project file
LIBS += -lChartboostPlugin
3. Lastly, which platform are you building on (Android or iOS)?