title: lektor server does not start under freebsd
body: <p>I have installed lektor via freebsd ports, there was no error. <code>lektor quickstart</code> also created my project but after I would like to start <code>lektor server</code> no matter which folder I am in or which flags do I add, I get this error:</p>
  <pre><code>Traceback (most recent call last):
    File &quot;/usr/local/bin/lektor&quot;, line 33, in &lt;module&gt;
      sys.exit(load_entry_point('Lektor==3.2.2', 'console_scripts', 'lektor')())
    File &quot;/usr/local/lib/python3.9/site-packages/lektor/cli.py&quot;, line 766, in main
      cli.main(args=args, prog_name=name)
    File &quot;/usr/local/lib/python3.9/site-packages/click/core.py&quot;, line 1053, in main
      rv = self.invoke(ctx)
    File &quot;/usr/local/lib/python3.9/site-packages/click/core.py&quot;, line 1659, in invoke
      return _process_result(sub_ctx.command.invoke(sub_ctx))
    File &quot;/usr/local/lib/python3.9/site-packages/click/core.py&quot;, line 1395, in invoke
      return ctx.invoke(self.callback, **ctx.params)
    File &quot;/usr/local/lib/python3.9/site-packages/click/core.py&quot;, line 754, in invoke
      return __callback(*args, **kwargs)
    File &quot;/usr/local/lib/python3.9/site-packages/click/decorators.py&quot;, line 84, in new_func
      return ctx.invoke(f, obj, *args, **kwargs)
    File &quot;/usr/local/lib/python3.9/site-packages/click/core.py&quot;, line 754, in invoke
      return __callback(*args, **kwargs)
    File &quot;/usr/local/lib/python3.9/site-packages/lektor/cli.py&quot;, line 471, in server_cmd
      from lektor.devserver import run_server
    File &quot;/usr/local/lib/python3.9/site-packages/lektor/devserver.py&quot;, line 9, in &lt;module&gt;
      from lektor.admin import WebAdmin
    File &quot;/usr/local/lib/python3.9/site-packages/lektor/admin/__init__.py&quot;, line 1, in &lt;module&gt;
      from .webui import WebAdmin
    File &quot;/usr/local/lib/python3.9/site-packages/lektor/admin/webui.py&quot;, line 7, in &lt;module&gt;
      from flask.helpers import safe_join
  ImportError: cannot import name 'safe_join' from 'flask.helpers' (/usr/local/lib/python3.9/site-packages/flask/helpers.py)
  </code></pre>
  <p>I did everything as it was described in quick start, so this is just a default installation. My os version is:</p>
  <pre><code>FreeBSD 13.1-RELEASE releng/13.1-n250148-fc952ac2212 GENERIC amd64
  </code></pre>
  <p>And my installed lektor version is:</p>
  <pre><code>Lektor, version 3.2.2
  </code></pre>
  <p>How should I fix this? Is that a known bug? I didn't found anything usefull while googleing.</p>