Error "MANIFEST.MF already exists in VFS" when creating new artifact

Question

I have a Java project that I used to be able to build artifacts from, but now I am unable to.

First, my project was building and I was able to create artifacts, but on running the .jar I was getting "Java Exemption Error". I checked to see what version of the compiler I was using (1.8) and made sure my machine was up to date.

Next I tried to fix any dependency issues by deleting and re-associating some of my external .jar files.

Then I deleted the artifact setting and tried to create a new one. Now I receive a

.../MANIFEST.MF already exists in VFS

error when trying to create a new artifact.

I'm using the latest version of Intellij. My source code can be found here: https://github.com/mjtik/PiccoApp.

I can provide screen shots if necessary.

*I have created many .jars in the past, not sure what changed in my project.

Any suggestions or guidance would be appreciated.

Answer 1

I solved my problem. Ever step I took lead me to the solution. The problem was with how I was creating the new artifact.

When creating the new artifact, I selected JAR and then a popup window displays default settings. It has me app module selected and the main class below is blank.

I was selecting the main class and it was producing an error. When I just accepted the default options left the main class blank, the artifact was created.

Answer 2

Another solution would be to just :

1. Navigate to $HOME$\IdeaProjects\ProjectFolder\src\META-INF and delete the MANIFEST.MF file in there.
2. Restart IntelliJ Idea
3. Go to Project Structure > Artifacts -> delete your project artifact setting
4. Add new artifact setting and reconfigure as required.