Apparently the problem is due to an incompatibility between the use of certain libraries (winapi and windows-sys) which use different versions of COM. At least so I deduce from the documentation I've read.

There's a workaaround:

On Cargo.toml, use.

[build-dependencies]
embed-manifest = "1.3.1"

And on the root of the project (not the src dir) create a build.rs file with the following content:

use embed_manifest::{embed_manifest, new_manifest};

fn main() {
    if std::env::var_os("CARGO_CFG_WINDOWS").is_some() {
        embed_manifest(new_manifest("Contoso.Sample")).expect("unable to embed manifest file");
    }
    println!("cargo:rerun-if-changed=build.rs");
}

This embeds a manifest together with the executable, solving the issue.

You can manually convert a tokio::main to a regular main by constructing a tokio runtime and telling it to block on a top-level future (e.g. an async block).

https://tokio.rs/tokio/tutorial/hello-tokio

That will at least help you break down the problem to locate the issue.

I don't know anything about Windows though. Maybe there's some per-thread setup that needs to be done in tokio's thread pool?