Problem in assigning DOI Prefix (Cannot Change DOI prefix)

I am using OJS 3.0.2. For trail of DOI plugin, I have changed DOI prefix to 10.1288 and now when actual I have DOI prefix as 10.18231, I cannot change the earlier DOI to actual DOI. I have tried changing the DOI prefix and reassigning also. However, once I fill the DOI prefix as 10.18231 and save it, and again check the settings, I find the DOI prefix changed back to 10.1288.

Kindly help me in this regard.

Hi @joapreditor

In OJS 3.0.2 the DOIs are not automatically assigned – the editor has to explicitly assign them – and the button/link “Reassign DOIs” in the plugin settings will just remove those already assigned, and will not assign the new ones.
In the next OJS release there will be a button/link that will enable to assign DOIs to all existing articles. S. this GitHub Issue i.e. changes needed for that: Add "Assign DOIs to all journal articles" button in the DOI plugin settings · Issue #2342 · pkp/pkp-lib · GitHub. Eventually you will be able to apply those changes and use that new function.