Partial Folder Structure For a OneDrive Account.

These are the hardest problem to troubleshoot.

It can happen when there is at least 1 publicly shared object (either a folder or file) under the OneDrive account, which makes it possible for external users to crawl it, but only the publicly shared objects will be returned. No error message is logged for these accounts, and you should verify that the required Site Collector Administrator permissions were granted.