SPR# SOSI6KJRHP Problem in 8.5.1 Upgrade

Why am I getting the problem below when trying to upgrade a client from 8.5 to 8.5.1 using smart upgrade?

(SPR# SOSI6KJRHP - Fixed a problem that caused Smart Upgrade Tracking to show Final Status as “Interrupted” on a successful multi-user Notes Client upgrade.)

How can I fix?

Subject: Because…

While the symptom appears to be the same, the cause is different. A fix for another instance of this issue was submitted to 8.5.2 although I can’t find the SPR# at this time.