If you unpack with 7zip or WinRar then the unpacked files are read-only. You then have to make them read/write before you can do anything with them.
If you unpack with RW_Tools they are automatically made read/write.
Which process did DTG say is a no-no? I realise that at one time their policy in support was to say that RW_Tools should not be used for anything! Despite that one of their directors did ask if I could write some utilities for them, but that came to nothing due to a change in staff. I think their real problem was that many RW_Tools users did not read the instructions on various subjects, and instead of asking me about problems they caused, they asked DTG support who of course had no idea what the user was talking about and caused them a lot of extra work.
Meanwhile, if you want a really good program to swap locos etc, try LuaCreator which is available from Rudolf Heijink in the Netherlands at
https://www.hollandhiking.nl/trainsimulator/ this is a beta version but works very well.
Mike