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

Question

As the title mentioned I have the following problem: I use Eclipse with Maven Nature and when I update my Maven Project, I get this error:

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

The solution that always comes back is the following:

• rightclick project, remove maven nature
• mvn eclipse:clean (with project open in eclipse/STS)
• (sometimes they suggest to do mvn eclipse:eclipse next)
• rightclick project and reenable maven nature

Now I exhaustively tried all combinations several times. But I always keep getting the above error. The error starting occurring when I had to mvn eclipse:eclipse the project. Before it was always running fine using only m2eclipse features and setting everything in eclipse.

Solution 1

I had to do it slightly different to work for me:

1. rightclick project, remove maven nature (or in newer eclipse, "Maven->Disable Maven Nature")
2. mvn eclipse:clean (with project open in eclipse/STS)
3. delete the project in eclipse (but do not delete the sources)
4. Import existing Maven project

Solution 2

• I just went to Properties -> Java Build Path -> Libraries and removed the blue entries starting with M2_REPO.

• After that, I could use Maven -> Update Project again

Solution 3

This is all you need:

1. Right-click on your project, select Maven -> Remove Maven Nature.

2. Open you terminal, navgate to your project folder and run mvn eclipse:clean

3. Right click on your Project and select Configure -> Convert into Maven Project

4. Right click on your Project and select Maven -> Update Project

Solution 4

After trying all these procedures it still didn't work for me. What did work was

1. go into File Explorer and delete the .classpath file under the project's root folder
2. run Maven update within Eclipse, and check Force update of Snapshots/Releases

Our current work required integrating a number of disparate projects so unfortunately use of SNAPSHOTs in a production environment were required (taboo in Maven circles)!

Solution 5

This issue (https://bugs.eclipse.org/394042) is fixed in m2e 1.5.0 which is available for Eclipse Kepler and Luna from this p2 repo :

http://download.eclipse.org/technology/m2e/releases/1.5

If you also use m2e-wtp, you'll need to install m2e-wtp 1.1.0 as well :

http://download.eclipse.org/m2e-wtp/releases/luna/1.1

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Comments

[Aritz]

Not necessary to remove maven nature at all.

[Adrian Ber]

Instead of 3 I deleted the .settings folder and refresh the project in Eclipse and instead of 4 I did Configure > Convert to Maven project.

[slash33]

Step 2 removed .classpath and .project even when the project was opened in Eclipse Juno.

[erhun]

It is working with an extra Maven->Update Project at the end of this steps. Thanks.

[NikhilWanpal]

@JJZabkar Probably this will help: stackoverflow.com/questions/10564684/…