Repository Groups don't store artifacts they simply aggregate artifacts from other repositories. If you are updated to a recent version of Nexus uploading to a group isn't possible.
Instead upload to a hosted repository.
Some very, very old version of Nexus in the 1.x release time period had a bug that allowed users to upload artifacts to repository groups. This bug has been fixed for years, but if you are running an old version of Nexus you might want to know how to fix this situation. The following process is suggested if you encounter a Nexus instance that has artifact published to a group.
- Copy these artifacts to the appropriate directory under sonaype-work/. Make sure that you copy them using the repository file structure of <groupId>/<artifactId>/<version>. If you have a Nexus instance with artifacts deployed to a group you will want to copy the contents of "sonatype-work/nexus/storage/<group-id>" to "sonatype-work/nexus/storage/<repo-id>".
- Delete the group's local storage by just deleting the "sonatype-work/nexus/storage/<group-id>"
- Repair all repository indexes using a manually scheduled task. See Scheduled Tasks.
Step 2 should be performed when the repository isn't running to minimize any potential issues. Once you've completed this process you may also want to restart Nexus.
In general, you should understand that Nexus is patched for security vulnerabilities and new features. If you are running an instance old enough to suffer from this bug, we strongly suggest that you upgrade your Nexus instance. Things did change a bit between 1.x and 2.x.