No problem. The ESP-IDF 4.0 introduced some internal changes to the structure of CMake statements used by it, so it took us some time to update VisualGDB so that it could automatically edit them.
Both ESP-IDF 3.3 and 4.0 are now supported by the following build: VisualGDB-5.5.1.3259.msi
Once you install it, the Tools->Manage VisualGDB Packages window will show the new toolchains compatible with ESP-IDF 3.3 and 4.0.
The new build also introduces the new property editing engine that uses schema files instead of hardcoded logic in order to locate and edit framework-specific CMake statements, so we should be able to react faster next time Espressif changes the statement layout again.