Hi Makis I am using a brand new completely blank project (as in step #2 in my 2nd last post). When checking those links they are for upgrading from older project versions. The changes they mention are already the default in 4.19 (ie my project source files do not need any of those modifications as they are already like that).
If I remove your plugin then the generate visual studio files command works without error.
Any other ideas? Do you have 4.19 from the Epic launcher installed yourself?