I've came across this error a couple of times now. If you're receiving this error you will see it 3-4 times in your SMSTS.log file before your task sequence will fail. Giving you a generic task sequence error. Unless you look in the SMSTS.log you will not see this error. After looking through my settings on my State Migration Point, I noticed that I had only 15 clients with Complete/In-Progress status. Well that should be fine as I have set my client max to 50.
The catch is the days I had set to retain my migration data. This was set to 30 days. This is pretty high , I know. I had it set this high because the is a new rollout and I didn't want to lose anyone's data. I wanted to have plenty of time to recover it if I needed to.
So even though my clients max was set to 50 and the SCCM console was only showing 15 Completed/In-progress. My Migration Point had the meta data for over 100 still stored. This was caused by me just deleting associations out of the console and not deleting the actual data. (Or allowing SCCM to do so) Rookie mistake.
To resolve the error I deleted the oldest 30 or so records from the Migration Point (the actual data, not the associations), and the OSD task sequence took off as intended.
Afterwards I adjusted my retention period to 10 days since I have the task sequence pretty much how I want it for now. Below is a screen shot.