The following error occurred: Error reading VS project settings

Initially I had the problem described here: https://bugreports.qt.io/browse/QTVSADDINBUG-1034
I fixed that by editing the registry directly as instructed here: https://forum.qt.io/topic/140525/register-at-least-one-qt-version

Now when I try to create a project using the wizard (Qt Widgets Application), I always get the following errors:

Followed by: 

I expect that this is because the project simply wasn't created.  The folder "J:\My Projects\Nintendo Synthy-4 Qt\Nintendo Synthy-4 Qt" exists but is empty (so is "J:\My Projects\Nintendo Synthy-4 Qt").  After creating the folder it didn't create the project file, so there was no project file to read.