An internal error occurred during: “Updating Maven Project”. java.lang.NullPointerException

Question

I\'m developing a Java EE web project. When I try to add a dependency, this error message appears. I use Eclipse Kepler.

An internal error occurred du

Answer 1

I encountered this same symptom and none of the solutions above were helpful. I finally got a stack trace of the problem by importing the ear project again to eclipse, and was able to trace this down to the org.eclipse.m2e.wtp.MavenDeploymentDescriptorManagement which was trying to delete a directory in windows' temp directory called ".mavenDeploymentDescriptorManagement", which caused an irrational NullPointerException from the java.io.File.exists() method, particularly because the code already had successfully done the same thing in a previous method with the same variable, then called file.isFile() without problem.

Checking this out on the file system revealed that the file could only be accessed with administrator privileges. Apparently I had at some point launched eclipse from an administrator console by mistake. In the end I just made hidden files visible in windows explorer and deleted the temporary file manually, which solved the problem.