I have problems with the NLM Metadata plugin. So I wanted to re-upload it by uploading the appropriate files. So I downloaded the latest version of OJS (3.1.1-2), but there in the folder /plugin/oaiMetadataFormats I did not find the “nlm” folder. So I downloaded the previous versions and only in 3.0.2 I found this plugin. Why is not it already in version 3.1?