sylvain.bonnemaison,
In case you are seeing NoClassDefFoundError, it means that the jar file is not present in the classpath. I would need to see the complete issue logged in your .log file. Please provide below details –
1. Open MyEclipse IDE, from menu options click on MyEclipse > Installation Summary > Installation Details. And copy and paste the same here
2. Clear your .log file located at [your workspace dir]/.metadata/.log, replicate the issue and copy and paste the issue logged in your .log here
3. Remove the “maven-resources-plugin” from the local repository on your machine and try building the project again. This would force maven related jars to be reloaded.
Let me know how this works for you