Reply To: Dummy content errors

We investigated your problem and see that it is not theme-related. Because we tried to import XML files manually through the default “WordPress Importer” interface and still have the same problems.

But we found some workaround on wordpress support forum https://wordpress.org/support/topic/failure-to-import-and-invalid-post-type-errors

Here is the actual instruction

1) Download and Install 7zip.
2) Right click on your .XML file -> 7zip -> Add to Archive. You can find XML files in basel/inc/dummy-content/
3) Change the “Archive format” to gzip and hit “OK”
4) Try to import the file again (using the .gz you just created) and it should work. Admin panel -> Import -> WordPress