OpenEMS Backend jar: no main manifest attribute

Hi Team, I am trying to install an OpenEMS for our company, but I am having an issue on Jar file.
Can anyone help me or give some advice to make it work? Thank you very much in advance.

Hi Moonlifes,

Did you follow the Build guide for OpenEMS Backend? There are two ways to build and run the jar file: in the Eclipse IDE or via console (Gradle):

Alternatively please try if you can run the Release artifact from Github, e.g. openems-backend.jar


PS: I moved this post to a separate topic.

Hi Stefan,

Appreciate your response. Yes I have followed the build guide for OpenEMS but seems there are certain wrong configuration with my jar file. I am using Eclipse IDE since it is not working via console. Please check the image below when I am trying to do it on console. Thank you

What’s the output of gradle tasks as suggested by the error message?

Hi Stefan, I just run the gradle tasks. Is this successful now?

I suggested gradle tasks, because it gives you a list of all possible tasks. But you need to execute it in the root folder of your OpenEMS path, i.e. where you did git clone. Try the following on linux:

mkdir -p ~/git/
cd ~/git/
git clone
cd openems
./gradlew tasks
./gradlew buildBackend

Apart from that I really recommend going through the Getting Started guide, because it covers all those steps (via Eclipse IDE) as well:


Hi Stefan, I have done your suggested cloning but I am unsuccessful.
Do you have an idea on this? Thank you


Sorry, have never seen this before. Maybe some firewall/proxy issue on your side? See…