This is just a bit of a pet peeve of mine. A paper is published, but the DOI doesn’t resolve nor is any metadata available. I don’t mean to blame anyone, I’m just trying to understand how this is a thing? Is the publishers? Is it Crossref? Any idea?
Here are three examples from the past few days (all linking to the landing pages):
10.1111/aje.12830
10.1111/1365-2664.13841
10.1111/ecog.05119
Sorry if this is kinda off-topic, but hoping someone in here might have a clue 
Hi dnoesgaard, I have checked all three DOIs and have found no problems:
10.1111/aje.12830 (not 10.1111/aje.12830 3 - DOIs do not have spaces)
ARTICLE: https://doi.org/10.1111/aje.12830 resolves to the journal article at https://onlinelibrary.wiley.com/doi/10.1111/aje.12830, which is fully open access.
METADATA: Entering the DOI into the Crossref Metadata Search at https://search.crossref.org, you get https://api.crossref.org/v1/works/10.1111/aje.12830, which gives full metadata including references.
10.1111/1365-2664.13841
https://doi.org/10.1111/1365-2664.13841 resolves to the journal articles at
https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2664.13841, which is fully open access.
METADATA: Entering the DOI into the Crossref Metadata Search at https://search.crossref.org, you get https://api.crossref.org/v1/works/10.1111/1365-2664.13841, which gives full metadata including references.
10.1111/ecog.05119 (not 10.1111/ecog.05119 1 - DOIs do not have spaces)
ARTICLE: https://doi.org/10.1111/ecog.05119 resolves to the journal article at https://onlinelibrary.wiley.com/doi/10.1111/ecog.05119, which is fully open access.
METADATA: Entering the DOI into the Crossref Metadata Search at https://search.crossref.org, you get https://api.crossref.org/v1/works/10.1111/ecog.05119, which gives full metadata including references.
Hope this helps. David Shotton (OpenCitations: http://opencitations.net)
Hi @davidshotton, thanks your comments.
I confirm that the DOIs now resolve, however, they did not at the time I posted my message 3 days ago. I don’t know if this is specific to Wiley or a general Crossref issue. Why would a paper be published without metadata being accessible at time of publication? I mean, the DOIs were on the landing pages, so I assumed they had been reserved?
Crossref has had intermittent problems with its metadata search recently. Isaac Farley,
Crossref Technical Support Manager (support@ccrossref.org) wrote to me on Feb 4th: “We have had some intermittent problems with the server that runs Crossref Metadata Search. We have had other members report the same problem and I have seen it myself a couple of times in the last week. Our technical team did deploy a patch for that earlier today, which should have helped. I am no longer getting that error during my afternoon (US central time). That said, I have noticed the error during my mornings, when we experience peak demand on the search interface.”
Hi - thanks @davidshotton for replying. Crossref Metadata Search is separate from the content registration process. To clarify the content registration process: the publisher registers the metadata with Crossref. There can be a delay at Crossref from when the publisher registers the content and we process it - this includes creating the DOI. Usually the registration happens right away or within a couple of hours. However, there was a slow down last week and things got backed up and we are still working through the backlog - so it looks like these examples were caught up in this. New content is then indexed in Crossref APIs and the search but the DOI will resolve. Crossref DOIs aren’t reserved in advance.
Thanks for the clarification, Ed.
Just saw another example (https://onlinelibrary.wiley.com/doi/10.1002/ece3.7237) which was published 2 days ago:
% date; curl -f --silent --output /dev/null --write-out ' %{url_effective} response: %{http_code}\n' https://doi.org/10.1002/ece3.7237
Wed Feb 10 09:37:38 CET 2021
https://doi.org/10.1002/ece3.7237 response: 404
% date; curl -f --silent --output /dev/null --write-out ' %{url_effective} response: %{http_code}\n' https://api.crossref.org/works/10.1002/ece3.7237
Wed Feb 10 09:38:52 CET 2021
https://api.crossref.org/works/10.1002/ece3.7237 response: 404
Is this still due to the backlog?