An error upon trying to execute Drupal Console I installed Drupal 8 into on my localhost, working under Windows 7 with OpenServer.
After it I tried to install Drupal Console using Composer.
Namely, this way

composer require drupal/console:~1.0 --prefer-dist --optimize-autoloader


It installed without errors. 
But when I'm trying to execute Drupal Console (with command "drupal"), there is an error on the console:

Fatal error: Cannot use Drupal\Console\Core\Bootstrap\DrupalConsoleCore as DrupalConsoleCore because the name is already in use in D:\OpenServer\domains\palomniki.local\vendor\drupal\console\src\Bootstrap\Drupal.php on line 11


Could you clarify me, how to solve this problem ? 

Frankly speaking, I managed to find answers of the error, where they advice to reinstall Drupal Console, but I don't know what they means. I tried to do remove this package, then to reinstall it, but I wasn't able to fix the error.
Drupal console global executable is not at the same version as your current project

go outside any drupal project and 
and execute: drupal self-update