I had this error for a long time. For me, the problem was that the CLI user couldn't write in the laravel.log when the couchbase client was trying to write a warning to it. Check user permissions.
I use couchbase nosql database by
ytake/laravel-couchbase package in my laravel 5.1 project
After install that package and run
php artisan serve i got error :
PHP Fatal error: Class 'CouchbaseN1qlQuery' not found in /var/www/html/eee/vendor/ytake/laravel-couchbase/src/CouchbaseServiceProvider.php on line 71 [Symfony\Component\Debug\Exception\FatalErrorException] Class 'CouchbaseN1qlQuery' not found