An internal error occurred during: "Updating Maven Project

when i convert to maven project the error is :

> An internal error occurred during: "Updating Maven Project".
> Unsupported IClasspathEntry kind=4

what's the problem?

This is all you need:

1. Right-click on your project, select Maven -> Disable Maven Nature.
2. Open you terminal, go to your project folder and do “mvn eclipse:clean”
3. Right click on your Project and select “Configure -> Convert into Maven Project”

Here is what worked for me: After the steps posted in Answer 21 above (the last being Convert to Maven Project), I did:

1. mvn eclipse:eclipse - this regenerates your .project and .classpath files (both of which were blown away by mvn eclipse:clean in step (2) above)

2. In Eclipse, I right-clicked my project(s) and then Maven > Update Project

I did not see the Unsupported IClasspathEntry kind=4 message anymore :)

As posted here, the problem is the command line eclipse project generation. So, do not use mvn eclipse:eclipse instead do:

1. delete your project from eclipse (without deleting it from your file system)
2. do mvn eclipse:clean in your command line inside your project folder
3. delete .classpath .project .settings in your project folder (if they still exist after doing 2.)
4. in eclipse import your project as an "Existing Maven Projects" and it should work flawlessly