Earlier today I was troubleshooting a deployment of Windows 10 v1607 via ConfigMgr OSD. During the "Use Toolkit" action, the task sequence failed with error 800700A1.
Normally that error can be cause by a typo in a run command line action, and the error translates to ERROR_BAD_PATHNAME. In this case however, it was because of a missing hard drive in the virtual machine I was testing on 🙂
After adding a hard drive, the task sequence run through just fine.
Happy Deployment, Johan