I am currently trying to mass prune members currently (we've got a lot of spammer accounts a few days ago) and the prune function doesn't seem to be working reliably. I have about 2000 users to prune, and it'll get through a handful... and then just stop. Any ideas why this could be happening?

Likely this would indicate that there is an issue it is encountering if it is just stopping and not progressing or background tasks are being ran by traffic and there is little traffic.

We would need to look further into this for you, however the access details on file appear to be incorrect or missing. Could you please update these details by visiting your client area, selecting the relevant purchase, then clicking "Review/Update Access Information" under the "Stored Access Information" section. 

We look forward to further assisting you.