Thanks for the assistance @Blue_Sialia .
No extension of the like, no. I tried the same thing from the browser on my iphone, same result. So it probably has to do with the projects. I get the same result for all of them, both for Android and IOS, but I should say that those are all projects that were migrated from the CocoonJS era.
I’m trying to setup a new project, but I’m facing a new problem here: When dragging my zip file in the appropriate space to upload it, I get “Operation failedReason: There was a problem processing your config.xml file.” at the end of the upload. There’s no config.xml file in the zip. This happens even with a very simple zip file containing only a blank html file. I do zip only the content of the folder, not the folder itself, as said in the documentation. Are there new requirements for zip files that didn’t exist before Cocoon.io ?
EDIT: The migrated projects didn’t have source code associated to them. I managed to upload a zip file to replace the source code of one of them, and compilation of the dev app (and presumably, normal compilation) seems to be working now. I still get the same issue trying to create a new project from the same zip, though.