With this error message Gerrit rejects to push a commit to a project which is configured to always require a Change-Id in the commit message if the commit message of the pushed commit does not contain a Change-Id.
You can see the commit messages for existing commits in the history by doing a git log.
To avoid this error you should use the commit hook or EGit to automatically create and insert a unique Change-Id into the commit message on every commit.
Missing Change-Id in the commit message
If the commit message of a commit that you want to push does not contain a Change-Id you have to update its commit message and insert a Change-Id.
If you want to upload a new change to Gerrit make sure that you have configured your environment so that a unique Change-Id is automatically created and inserted on every commit as explained above. Now you can rewrite the commits for which the Change-Ids are missing and the Change-Ids will be automatically created and inserted into the commit messages. This is explained here.
If you want to update an existing change in Gerrit by uploading a new patch set you should copy its Change-Id from the Gerrit Web UI and insert it into the commit message. How to update the commit message is explained here.
Part of Gerrit Error Messages