I have a download link (40mb+ file) when clicked and confirm where to save file, make another click on same link and got crash. 

Tried to make sample of crash, and didn't yet face such behavior: on second click app didn't made something (not showed download dialog), but also not crashed. Will provide sample as soon as got reproducible one.

Debug:
<img width="1331" alt="screen shot 2017-02-16 at 1 24 09 pm" src="https://cloud.githubusercontent.com/assets/1834053/23017440/56041e32-f44b-11e6-8d5c-f1ff6ad671cd.png">

Report:
<img width="1398" alt="screen shot 2017-02-16 at 1 25 28 pm" src="https://cloud.githubusercontent.com/assets/1834053/23017568/db45549e-f44b-11e6-8f74-650b0f2cc756.png">

Any idea what can affect such problem? 

As I see from report last triggered method was webContents.loadURL, but didn't understand why it was called since I have webContetst.session event 'will-download' called, that had to be triggered after webContents.downloadURL, not loadURL.

atom/browser/api/atom_api_web_contents.cc
const SkBitmap& bitmap,
                       content::ReadbackResponse response) {
  callback.Run(gfx::Image::CreateFrom1xBitmap(bitmap));
}
}  
WebContents::WebContents(v8::Isolate* isolate,
                         content::WebContents* web_contents,
                         Type type)
    : content::WebContentsObserver(web_contents),
      embedder_(nullptr),
      zoom_controller_(nullptr),
      type_(type),
      request_id_(0),
      background_throttling_(true),
      enable_devtools_(true) {
  if (type == REMOTE) {
    web_contents->SetUserAgentOverride(GetBrowserContext()->GetUserAgent());
    Init(isolate);
    AttachAsUserData(web_contents);
  } else {
    const mate::Dictionary options = mate::Dictionary::CreateEmpty(isolate);
    auto session = Session::CreateFrom(isolate, GetBrowserContext());
    session_.Reset(isolate, session.ToV8());
    InitWithSessionAndOptions(isolate, web_contents, session, options);
  }
}
WebContents::WebContents(v8::Isolate* isolate, const mate::Dictionary& options)