I’ve haven’t heard of that happening with C++, just launch the Editor from Visual Studio and you can debug it.
Unity might open, but all the script components will be gone from everything, with no clue how to reattach everything. Happens regularly when working on a team project in it, even with Perforce managing it, it’s a complete pain for developing as a team.
It runs on older hardware, because it’s an older engine. Compare it to UE3 for last gen stuff.