With Grails 2.2.1: No such property: mergedConfig Error

[jolo2000]

Hi, since I ported my app to Grails 2.2.1,
I get the following error message:

No such property: mergedConfig for class: org.codehaus.groovy.grails.commons.DefaultGrailsApplication. Stacktrace follows:
Message: No such property: mergedConfig for class: org.codehaus.groovy.grails.commons.DefaultGrailsApplication
Line | Method
->> 53 | makePdf in org.wkhtmltox.WkhtmltoxService

I suspect that it has to do with the "Plugin Config" -Plugin, but I have no idea how to fix this error.

Any hints are greatly appreciated
Johannes