I know it’s been a few years, but this is the closest I found to an answer. I am trying do what you all did here, but I have a twist. I need parent forums. I tried the post_parent on the csv file and it didn’t work, it just create a 404 error where the url was a bunch of numbers. Changed the permalinks, nothing.
I also tried another importer, but got half way and it started locking up – php memory errors.
I am trying import a few thousand lines in each csv file.
Has anyone been able to find a solution or fix?