Import error: file_type: undefined

Import via pasted xml continues to work, so looks like issue is 100% file upload / import, likely due to file entity changed.

Please add application/zip to mime types of document at /admin/structure/file-types/manage/document/edit

This should solve the issue

going to implement a hook_update_N to update this setting if file_enity module is enabled

also I can add a warning message on content import page

Indeed, adding the MIME type here /admin/structure/file-types/manage/document/edit fixed the issue.
Thank you!

Hi,
I have created patch and added hook_update_N as per suggested in #5, With addition of application/zip, I have to also added application/octet-stream for YAML file. Please review patch.

I have reviewed the patch(#7) manually. It works fine.