title: MongoDB migration ABP
body: <p>I have installed the ABP with mongoDB and it is on my local machine but having this issue when running the .DBMigrator</p>
  <p>[10:52:51 INF] Started database migrations...
  [10:52:51 INF] Migrating schema for host database...
  Unhandled exception. System.ArgumentNullException: Value cannot be null. (Parameter 'connectionString')
  at MongoDB.Driver.Core.Misc.Ensure.IsNotNull[T](T value, String paramName)</p>
  <p>&quot;ConnectionStrings&quot;: {
  &quot;Default&quot;: &quot;mongodb://localhost:27017/HelloWord&quot;
  },</p>