Importing an exported file doesn't work

[MeFisto94]

Hey Guys,
this should be pretty easy to fix:
I was working on a project from scratch, exporting it as json (download).
After some changes, the import failed, because the file didn't specify "openapi": "3.0.0", so this seems to be missing in the exporter or I was doing things wrong

Edit: The same problem happens when trying to validate the schemas using the Wizards, so even though my file now has an "openapi" directive, the exporter is swallowing it thus making the validation fail