[Qt-creator] QString "not accessible" in Creator 4.6.2?

[Bob Hood]

I have installed Creator 4.6.2 (normally, I use 4.0.3) and have started a new 
project with it.  Prior to installing it, I already had Visual Studio 2017 
15.4.7 installed, along with Windows SDK v10.1.17134.12 with "Debugging Tools 
for Windows".  Creator 4.6.2 automatically found the debugging tools, and I 
reconfigured my Kits accordingly for use with Qt 5.9.4 Desktop (which I built 
myself using Visual Studio 2017, so they are ABI compatible).

I'm debugging into my Qt application, and I'm getting "not accessible" the 
Locals pane for QString and QStringList.  Was there some further set-up I 
needed to perform?  I don't recall having this issue with 4.0.3.