CrossRef plugin submission failure

Hi. The last batch of articles on OJS has failed to assign DOIs, even though it was all working fine before and afaik nothing has changed in the interim. Seems that the plugin is sending correctly, but failing to register. Failure notification says:

Submission was not successful! The DOI registration server returned an error: '1 - HTTP/1.1 100 Continue

HTTP/1.1 400 Bad Request
server: Apache-Coyote/1.1
crossref-deployment-name: ds3-2
content-length: 0
date: Tue, 22 Jun 2021 08:48:20 GMT
permissions-policy: interest-cohort=()

What should I do to fix this? Does anyone know what the error is identifying?

Thanks for your help.

OJS is version

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Hi @DavidR1,

Here is posts of users encountering similar errors here and addressing them here (though verifying their crossref credentials): CrossRef XML Explort Plugin - DOI Submission error - #2 by bozana

Perhaps you could try that and let me know if it works?

And, just a note, that the version of OJS that you’re using (3.0) is no longer supported by PKP. I recommend that you upgrade to the newest version of OJS, as there are some improvements in OJS and the Crossref plugins that you may wish to take advantage of. Along with that, you may wish to upgrade your Crossref plugin.

Upgrading instructions are available in the PKP Administrator’s Guide .

Information about the latest version of OJS can be found on the PKP Website

The Crossref documentation can be found here: Crossref OJS 3.2+ Manual

Best regards,


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Thanks. I’ve checked, and they’re correct. Tried a few different variations too. Same thing.

I take the point about upgrading - but this version of OJS and the plugin worked before, and given nothing has changed, I don’t want to start messin with that until the basic problem is identified.

Any other options?

Thanks, David

We are still investigating with Crossref, but it appears that they may have dropped support for the API endpoint which was used up until OJS 3.1.2.

This same endpoint was used in all OJS 2.x Crossref submissions, and in early OJS 3.x code, including

In an open ticket with Crossref, their support reports that you should still be able to download the XML export from OJS and upload that manually. This should, however, be considered to be a secondary workaround to upgrading to a more recent version of OJS. OJS is extremely old, and is subject to a number of security advisories. [C.f. #3805 #3944/#4024 #5302 #5871]

Hello, I have the same problem with OJS and the plugin worked before.
I just wanted to mention it and while looking for a solution

Elena Cruz
Screenshot (81)

Hi ,

I am also observing exactly the same error.




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The API endpoint “” stopped working a few weeks ago, hence this errors with older version of OJS and (the corresponding CrossRef plugin). But appears to be back online, so everything should be alright now.

The new CrossRef plugin with newer version of OJS uses a different API enpoint and specifications: Synchronous REST API Deposit v2 | Crossref Knowledge Base

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@ gonperes

Thank you for the update - it is reassuring. We are running on OJS 2.4.8. and we noticed the registrations stopped working around 17/18 June 2021.

Could you guide me, will the old API be terminated indefinitely and by when?

I have no idea if or when the old API will be terminated.
They probably tried to disable it in June, but after some complaints, they must have enabled it back to life:

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@ gonperes

I value your prompt response and the link to Crossref Forum - thankful that they brought it back to life!

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Remember that you can still upload manually (download the xml and upload via crossref upload form).

Is not ideal, but will help if you are in a hurry.

Hi all, I’m Bryan Vickery, Director of Product at Crossref. Our analysis of the usage of the v1 deposit suggested that it wasn’t being used, and we didn’t have information on the installs of older versions of OJS. At least now we know it is, by a few of you.

Typically we would not end the life of a service so swiftly, however - we are about to release a new version of our REST API on July 13 and we can’t guarantee that this old v1 deposit API will continue to work after that date.

A change we made on June 10th should not have removed the v1 deposit API from use, but having reverted that change, and noted that users can register content again, we can only assume that it did. We apologise for the inconvenience.

In summary, we will cutover to our new REST API on July 13th. The v1 deposit API is deprecated and unsupported - if, during the REST API roll out, the v1 deposit API breaks, we may not be able to fix it I’m afraid.

If that happens, you can continue to export your xml, and upload it to Crossref’s systems or you could, and probably should, upgrade your OJS instance to a supported version that makes use of the v2 deposit API.


Please conform that the v2 legacy deposit API (XML) will still function after the cutover to the REST/JSON API, and when is the planned termination date for the legacy v2 API?

It seems that the OJS3 plugin also still uses the legacy v2 API (XML), are there any plans from PKP to update this plugin to support the new REST/JSON API? GitHub - pkp/crossref-ojs: A Crossref plugin for OJS.

Hi, I should maybe clarify.

The JSON / REST API is a separate API for metadata retrieval, but because of the way our APIs were organised we couldn’t guarantee that the v1 deposit API would continue to work when we released the latest version of our JSON / REST API.

The v2 deposit API will still continue to function and is our current deposit API. PKP does not need to update.

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Thank you, appreciate the clarification and guidance.

Unfortunately, OJS 2.4x still uses the v1 deposit API, which doesn’t work currently. Is there a plan to update this plugin in OJS 2.4x?

Hi Brian, Can you provide a status update on the V1 Deposit API. I think many still use OJS 2.4x. Thanks.

And, as a due paying crossref member, it would have been nice to receive SOME notice of this change. A simple email and sampling would have shown that OJS 2.4x is still in use.

Thank you.


May we know if the XML files generated with the older version of OJS (like will remain possible?
At the moment it works well and can be used as a valid alternative to register/activate DOIs with Crossref.

Thank you.

Hi again. Our analysis of the usage of our dedicated OJS v1 deposit API (used in older versions of OJS, 3.1.1 and earlier) suggested that it wasn’t being used, and we didn’t have information on the installations of older versions of OJS. It turns out there are still a few of you.

Typically, we would not intentionally remove a service so suddenly, without notifying users, however, in the final stages before we released a new version of our REST API (July 13) we discovered that it might have an impact on this OJS v1 deposit API. The v1 deposit API was deprecated and unsupported, as is the case for the older versions of OJS as notified by PKP. We took the decision to release the new REST API knowing that if the v1 deposit API were to break, we may not be able to fix it, but that there were workarounds for our members:

  • you can continue to export your xml, and upload it to Crossref’s systems; or
  • you could—-and probably should—-upgrade your OJS instance to a supported version that makes use of the v2 deposit API (OJS 3.1.2 or higher).

On rolling out our new REST API the v1 deposit API did indeed break, and we’re not able to make it work again. I’m really sorry that we didn’t communicate that this would happen and that it has caused some disruption to a few of our members registering content automatically via OJS. I will ensure we learn lessons from this and update our deprecation plans for the future.

A previous message from PKP is here

And details on upgrading your OJS is here