I have found the following for: https://pteropaste.com/6tldo9eghefm
@terse solar; You have configured your Redis instance to require a password and are not providing one. Add your redis password in the .env hidden file located at /var/www/pterodactyl and try again or disable.
You can open it directly with nano /var/www/pterodactyl/.env. Refresh config cache with cd /var/www/pterodactyl && php artisan config:clear