Servers that will not connect, failed deploys, 502s and certificate problems.
Read the reason SrvYard recorded, then work through the checklist on the server page, running the repair commands in your provider's console if needed. SrvYard rechecks about every five minutes and returns the server to Ready by itself. See Fix a server that will not connect.
Open the deployment and read the first error line in its output, not the last. The Why it failed card, where your plan includes it, gives a plain-language hint. Then match the message to the usual causes. See Find out why a deployment failed and fix it.
Nginx is running but the program behind it, PHP-FPM or a Node.js process, did not answer. Check the services, that the site's PHP version exists, and the Nginx error log. It often follows a deployment or a PHP change. See Fix a 502 Bad Gateway on your site.
DNS, then port 80, then rate limits, then DNS validation, in that order. A failed request never replaces a working certificate, but a site set to Force HTTPS with none gives visitors an error. See Find out why a certificate failed and issue it again.
Three different problems look alike: DNS still points at another machine, Nginx did not recognise the name, or the site was never deployed. The SrvYard placeholder means the request arrived but nothing was deployed. See Fix the wrong site, an empty page or a placeholder after a DNS change.
The worker is missing or stopped, listens to a different connection or queue than your app uses, runs old code, or QUEUE_CONNECTION is sync. Check the worker on Processes, then restart it. See Fix queued jobs that are not being processed.
First find what uses it on the Monitoring tab and with du, then clear old logs and caches, and lower Deployments to keep so fewer releases stay. Take a backup before deleting anything you did not create. See Fix a full disk, low memory or a slow server.