An internal error occurred during: "Updating Maven Project".

after a maven update aI obtain the following:
java.lang.LinkageError: loader constraint violation: loader (instance of org/eclipse/osgi/internal/loader/EquinoxClassLoader) previously initiated loading for a different type with name "org/apache/maven/project/MavenProject"
at org.springframework.ide.eclipse.maven.internal.core.SpringProjectConfigurator.doConfigure(SpringProjectConfigurator.java:42)
at org.springframework.ide.eclipse.maven.AbstractSpringProjectConfigurator.configure(AbstractSpringProjectConfigurator.java:43)
at org.eclipse.m2e.core.project.configurator.AbstractLifecycleMapping.configure(AbstractLifecycleMapping.java:120)
at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager$3.call(ProjectConfigurationManager.java:501)
at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager$3.call(ProjectConfigurationManager.java:1)
at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.executeBare(MavenExecutionContext.java:176)
at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:151)
at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.updateProjectConfiguration(ProjectConfigurationManager.java:494)
at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.updateProjectConfiguration0(ProjectConfigurationManager.java:432)
at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager$2.call(ProjectConfigurationManager.java:345)
at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager$2.call(ProjectConfigurationManager.java:1)
at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.executeBare(MavenExecutionContext.java:176)
at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:151)
at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:99)
at org.eclipse.m2e.core.internal.embedder.MavenImpl.execute(MavenImpl.java:1351)
at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.updateProjectConfiguration(ProjectConfigurationManager.java:342)
at org.eclipse.m2e.core.ui.internal.UpdateMavenProjectJob.runInWorkspace(UpdateMavenProjectJob.java:77)
at org.eclipse.core.internal.resources.InternalWorkspaceJob.run(InternalWorkspaceJob.java:38)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)

---------------- ECLIPSE PART

eclipse.buildId=4.4.2.M20150204-1700
java.version=1.8.0_66
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=it_IT
Framework arguments: -product org.eclipse.epp.package.jee.product
Command-line arguments: -os win32 -ws win32 -arch x86 -product org.eclipse.epp.package.jee.product