Evaluate expression dialog no longer works in VO 2.8 SP4b, build 2838

[ThomasWYale]

In anticipation of re-converting my system to X#, I've been developing in VO 2.8 SP4b, build 2838, which is presumably the last version. In any event, it's the version I've been using for years. When I go into debug mode and open the "Evaluate an expression" dialog, the dialog no longer works. At one point it displayed junk for any entered expression, then the wrong value of a previously assigned variable, now it just displays NIL.

I had exported all AEFs, uninstalled VO, deleted the remaining directories under c:/cavo28, reinstalled VO which recreated the directory, and re-imported the AEF containing my system. Same problem. I've also reindexed the project several times, but the result is NIL or some other value no matter expression I enter. What is causing this? Windows 10 updated a few days ago. Could that be it?