title: cvc-complex-type.2.4.a: Invalid content was found starting with element 'base-extension'. One of '{layoutlib}' is expected
body: <p>I am facing this issue many times when i download project from github
  i am using new Android studio(bumble bee)
  please help me if any body knows</p>
  <p><a href="https://github.com/fjbatresv/arcore_solar_system.git" rel="noreferrer">https://github.com/fjbatresv/arcore_solar_system.git</a> (this is the project which i am downloading in bumble bee)</p>
  <p>There are not any gradle issue</p>
  <p>actually i have tried many solutions from stack over flow but i am getting solutions for gradle but it is not an gradle related error.</p>