Unable to add a Qt version in VS 2019 Pro

== Qt Visual Studio Tools version 2.9.1 (rev.6)
Initialized in: 282.23 msecs
 Main (UI) thread: 132.94 msecs
--- qmake(19152): started C:\SOURCE\AGEXTLIBS\QT-5.15.2\V142-X64\bin\qmake.exe
--- qmake: Querying persistent properties
--- qmake(19152): exit code 0 (44.61 msecs)
Value cannot be null.
Parameter name: path1
Stacktrace:
 at System.IO.Path.Combine(String path1, String path2, String path3)
 at QtVsTools.Core.QMakeConf..ctor(VersionInformation versionInfo, QMakeQuery qmakeQuery)
 at QtVsTools.Core.VersionInformation.GetQMakeConfEntry(String entryName)
 at QtVsTools.Options.QtVersionsPage.SaveSettingsToStorage() in C:\dev\source\qtlabs\vstools\QtVsTools.Package\Options\QtVersionsPage.cs:line 117
Cannot delete a subkey tree because the subkey does not exist.
Stacktrace:
 at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
 at Microsoft.Win32.RegistryKey.DeleteSubKey(String subkey, Boolean throwOnMissingSubKey)
 at Microsoft.Win32.RegistryKey.DeleteSubKey(String subkey)
 at QtVsTools.Core.QtVersionManager.RemoveVersion(String versionName)
 at QtVsTools.Options.QtVersionsPage.<SaveSettingsToStorage>g__RemoveVersion|10_0(String versionName) in C:\dev\source\qtlabs\vstools\QtVsTools.Package\Options\QtVersionsPage.cs:line 95

C:\Source\AGEXTLIBS\qt-5.15.2\v142-x64\bin>qmake.exe -query
QT_INSTALL_HEADERS:C:\Source\AGEXTLIBS\qt-5.15.2\include
QT_SYSROOT:
QT_INSTALL_PREFIX:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64
QT_INSTALL_ARCHDATA:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64
QT_INSTALL_DATA:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64
QT_INSTALL_DOCS:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64/doc
QT_INSTALL_HEADERS:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64/include
QT_INSTALL_LIBS:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64/lib
QT_INSTALL_LIBEXECS:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64/bin
QT_INSTALL_BINS:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64/bin
QT_INSTALL_TESTS:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64/tests
QT_INSTALL_PLUGINS:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64/plugins
QT_INSTALL_IMPORTS:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64/imports
QT_INSTALL_QML:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64/qml
QT_INSTALL_TRANSLATIONS:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64/translations
QT_INSTALL_CONFIGURATION:
QT_INSTALL_EXAMPLES:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64/examples
QT_INSTALL_DEMOS:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64/examples
QT_HOST_PREFIX:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64
QT_HOST_DATA:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64
QT_HOST_BINS:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64/bin
QT_HOST_LIBS:C:/Source/AGEXTLIBS/qt-5.15.2/v142-x64/lib
QMAKE_SPEC:win32-msvc
QMAKE_XSPEC:win32-msvc
QMAKE_VERSION:3.1
QT_VERSION:5.15.2