The university where I work is in the process of migrating from OJS 2.4.8 to OJS 3.1.x, but we are running into some problems. Our IT guy has been trying to export whole journal numbers from the OJS 2.4.8 page using the Journal Management > Import/Export Data menu and the first option in the list which says Articles & Issues XML Plugin: Import and export articles and issues. When he exports an issue that way and then goes to import it in the 3.1.x using the Tools > Import/Export tab and then the first option in the list which says Native XML Plugin, it gives an error which says “The file could not be uploaded or revised.”
I am attaching screenshots of the old 2.4.8 page, the new 3.1.x page, and the error message. Are we using the wrong import tool in 3.1.x? What is the way to import a whole issue?