Anyone who has a project set with a bunch of jar projects and an outer war one has probably had occasion to be working along and then suddenly, trying to raise the log level doesn‘t work. The main way this occurs is that logback is an implementation of the slf4j standard. But there are other implementations, and if they end up in your project, you will get an error about multiple bindings.
The simplest way to resolve this (with the m2eclipse plugin) is to go into the dependencies view and type in slf4j and make sure all you are seeing is the following:
If you see slf4j coming in from any other jars, just highlight, right click and choose Exclude Maven Artifact, comme ça:
BTW, there‘s a new version today: 0.9.29. Went looking for some release notes or something. That project website looks like it was commissioned by a state agency. And I guess I knew this, but they have an eclipse plugin that supports filtering! But they don‘t have an update site.. ??