why drash with specific version causes error on deno?

I'm exploring deno. I just got an issue while trying to start my (first ::) deno server, output saying "404"

server file is like:

import { Drash } from "https://deno.land/x/drash@v1.0.0-rc1/mod.ts";

const server = new Drash.Http.Server({
  response_output: "application/json",
  resources: [],
});

server.run({
  hostname: "localhost",
  port: 2803,
});

Command returned:

➜  helloDeno deno run --allow-net app.ts
Compile file:///home/totone/dev/solo/projects/helloDeno/app.ts
Download https://deno.land/std@v1.0.0-rc1/http/server.ts
Download https://deno.land/std@v1.0.0-rc1/http/http_status.ts
Download https://deno.land/std@v1.0.0-rc1/testing/asserts.ts
Download https://deno.land/std@v1.0.0-rc1/io/bufio.ts
Download https://deno.land/std@v1.0.0-rc1/io/readers.ts
Download https://deno.land/std@v1.0.0-rc1/mime/multipart.ts
Download https://deno.land/std@v1.0.0-rc1/http/cookie.ts
error: Uncaught Error: Import 'https://deno.land/std@v1.0.0-rc1/io/readers.ts' failed: 404 Not Found
    at unwrapResponse ($deno$/ops/dispatch_json.ts:43:11)
    at Object.sendAsync ($deno$/ops/dispatch_json.ts:98:10)
    at async processImports ($deno$/compiler.ts:736:23)
    at async processImports ($deno$/compiler.ts:753:7)
    at async processImports ($deno$/compiler.ts:753:7)
    at async processImports ($deno$/compiler.ts:753:7)
    at async processImports ($deno$/compiler.ts:753:7)
    at async compile ($deno$/compiler.ts:1316:31)
    at async tsCompilerOnMessage ($deno$/compiler.ts:1548:22)
    at async workerMessageRecvCallback ($deno$/runtime_worker.ts:74:9)

At beginning, I though that it was a bad use of --allow-net deno permission, but I tried once to reload server without a specific version for drash & it worked.

➜  helloDeno deno run --allow-net app.ts
Compile file:///home/totone/dev/solo/projects/helloDeno/app.ts

So the issue is near @v1.0.0-rc1 package version. Who can help me understanding the reason of this behaviour?

Thanks