I assume you are running OJS 2.x. What specific version are you running? Most recent version (as of 2.4.5 or better) should provide an additional message in that error you see in the popup which better describes the specific problem.
I forgot to say one thing, I started working with ojs a few weeks ago, so i do not know much, I did the update from 2.3.3 to 2.4.8.1 and the errors with php and DOI went searching the web to solve.
I’m pretty sure the rest of the error message is being masked by the untranslated error message. It should either say “No response from server” or should describe a status code and server response.
Can you try re-registering the article in a language which has a full translation, such as English? This should provide the full response. Alternately, using the “Translator” plugin, you could translate the key “plugins.importexport.crossref.register.error.mdsError”, leaving the variable {$param} as-is. That variable will be replaced by the detailed error message.
You would use the CrossRef plugin, but instead of Registering the DOIs directly, Export or Download the XML (phrasing depends on your version), then upload the results to CrossRef. Finally, mark the successfully uploaded DOIs as Registered.
This problem seems to have recurred at the CrossRef end. We are experiencing the very same problem as described in this thread. We have articles that were originally auto-submitted to CrossRef weeks ago, but are still marked as “Submitted” in OJS, and the DOIs/articles not showing up in CrossRef.
CrossRef’s answer to the problem:
If you take a look at the error message supplied in the logs from your recent deposits, you’ll see that it begins “Error: cvc-enumeration-valid: Value ‘’ is not facet-valid with respect to enumeration…” then lists many file types and ends with “…Error: cvc-attribute.3: The value ‘’ of attribute ‘mime_type’ on element ‘resource’ is not valid with respect to its type, ‘null’.”
What all that means is that your files include a mime_type attribute with no data specified for the mime type, e.g.:
This appears twice in the deposit you provided as an example, and will necessarily cause your deposits to fail.
Because OJS is not our product, I can’t advise you as to how to modify your OJS instance or OJS/Crossref plugin to remove the empty mime_type attribute. You’ll need to contact OJS’s support team or search their community help forums for more information.
Anyone know how to 'remove the empty mime_type attribute?