If the log4j 1.x API is on the classpath (e.g. in a Syncope-based project with additional dependencies), Syncope >= 1.2.0 tries to write a velocity.log-File. Startup fails if this is not possible, e.g. because write access to the file system is not granted to the Tomcat process. This used to work in Syncope 1.1.X.
Syncope's VelocityEngineFactoryBean should explicitly configure Velocity to use Commons Logging, as Spring's VelocityEngineFactory bean does, which was used in 1.1.X.
See the discussion on the dev mailing list: