No provider for NgbModalStack
<p>For some reason, I am suddenly getting this error out of the blue, with no code changes. Any ideas what would be causing this?</p>

<p>I was able to solve this with adding <code>NgbModule.forRoot()</code> to my imports,
but now I get this error:</p>

<blockquote>
  <p>Property 'forRoot' does not exist on type 'typeof NgbModule'.</p>
</blockquote>

<p>the application is running fine otherwise.</p>