Additional uncaught exception thrown while handling exception.

Original

MongoConnectionException: No candidate servers found in MongoCollection->findOne() (line 27 of /home/admin/www/drupal/releases/20170213130907/sites/all/modules/contrib/mongodb/mongodb_cache/mongodb_cache.inc).

Additional

MongoConnectionException: No candidate servers found in MongoCollection->findOne() (line 27 of /home/admin/www/drupal/releases/20170213130907/sites/all/modules/contrib/mongodb/mongodb_cache/mongodb_cache.inc).