Updated to 4.2. dropins folder issue


I updated knime to version 4.2 by downloading it and re-installing. I had to re-install extensions which was fine since knime can automatically do it.

The problem is I had a custom extension (.jar file) that worked in the previous version when I placed it in the dropins folder (C:\Program Files\KNIME\dropins). Now, the node is not showing in the repository when I place the file there and restart knime. Is there another way to install these .jar files?

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This is definitely related to version 4.2. I tested both 4.1.3 & 4.2 on a different computer.

4.1.3 recognizes the jar file and shows the node in my repository.

4.2 doesn’t load the node or shows an error or anything in the log file

By the way, the node was made by a 3rd party (alvaScience descriptors). Wondering if I can install two versions of knime on my computer

Yes you can since KNIME does just live in its folder. Two restrictions:

  • you can use the same workspace but not at the same time
  • workflows saved with the later version might create a warning when opened with the older version and some newer nodes might not work

Hi @tnad,
can you contact the developers of that custom extension to make sure it is compatible with KNIME AP 4.2? Some changes we have made require adaptions in extensions. Independent of that, using the drop-in folder is not recommended, instead plug-ins should be installed from an update site. That way you also receive better error messages if something goes wrong.


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The custom extension was moved to an update site and the installation now works. Thanks.


What kind of changes have been made and where to adapt them? Is there a guide, link or doc somewhere? Because I have the same issue…

Thank you!

Hi @EggOfFitch,

We are currently investigating if we can re-enable the drop-in folder functionality. It does not work at the moment. However, we strongly recommend not to the drop-in folder anyway, the best way forward for you is to use an update site as described in this guide:


Hi all,
My version 4.1.2 shows the node after I copied .jar file into dropins
Now I have the same issue on Knime AP version 4.2

My workaround is using local update site
or when you export your project, choose Install into host (on your local repository), and restart your knime.

Thank you

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Just to add info that dropins folder functionality is re-enabled with KNIME version 4.2.1.

Note: Using dropins is highly discouraged and you should switch to a proper installation of extension as soon as possible. Eclipse itself may remove this deprecated feature at any time.