WordPress continually generated “Failed to import” and “Invalid post type” errors when was trying to import a theme .xml file using its Importer plugin.
The .xml file was also not recognizing there were any authors in the file, looked like this
1. Import author: ()
or create new user with login name:
or assign posts to an existing user:
I FINALLY got the data to import thanks to this post in wordpress.org forum.
1) Download and Install 7zip.
2) Open a directory in your computer where you saved the XML file. Right click on your .XML file -> 7zip -> Add to Archive
3) Change the “Archive format” to gzip and hit “OK”. You’ll now see your file with a .gz extension
4) Try to import/upload the file again (selecting the .gz you just created)