title: sumo Error: Vehicle '0' has no valid route. No connection between edges 'gneE17' and 'gneE20'
body: <p>I have been working with Netedit for some times now. But when I perform the simulation on sumo gui all I get everytime is <em>Error: Vehicle '0' has no valid route. No connection between edges 'gneE17' and 'gneE20'. Loading of net-file failed. Quitting (on error)</em> . </p>
  
  <p>Please note here that <em>gneE17</em> is the ID for the beginning of the route. Also, below find the part code for the traffic data. </p>
  
  <pre><code>    &lt;routes&gt;
      &lt;vType id="type1" accel="3" decel="1.5" sigma="0.5" length="5" maxspeed="70"/&gt;
      &lt;route id="route0" color="1,1,0" edges="gneE17 gneE20 -gneE18 gneE21 "/&gt;
      &lt;/routes&gt;
  
      &lt;flow id="type1" color="1,1,0" begin="0" end="3600" VehsPerhour="200"&gt;
      &lt;route edges="gneE17 gneE20 -gneE18 gneE21"/&gt;
      &lt;/flow&gt;
  </code></pre>