replit-common-errors

# Replit Common Errors ## Overview Quick reference for the 10 most common Replit errors with real solutions. Covers container lifecycle, Nix configuration, database, deployment, and networking issues. ## Prerequisites - Replit Workspace access - Shell tab for diagnostics - Console tab for error logs ## Error Reference ### 1. Container Sleeping / App Goes Offline ``` Error: Your Repl is sleeping. Run it to wake up. ``` **Cause:** Free/Hacker plan Repls sleep after ~5 minutes of inactivity. **Solution:** - Use Replit Deployments (Autoscale or Reserved VM) for always-on - Or set up external keep-alive pinging (UptimeRobot, cron-job.org) - Check: Settings > Always On (deprecated in favor of Deployments) --- ### 2. Port Binding / Webview Not Loading ``` Error: EADDRINUSE: address already in use :::3000 ``` **Cause:** Previous process still holding the port, or hardcoded port conflicts. **Solution:** ```bash # Find and kill the process lsof -i :3000 | grep LISTEN kill -9 <PID> # Or use environment variable for port ``` ```typescript // Always use PORT env var const port = parseInt(process.env.PORT || '3000'); app.listen(port, '0.0.0.0'); // Must be 0.0.0.0, not localhost ``` --- ### 3. Nix Package Build Failure ``` Error: error: Package 'python-xyz' not found in channel 'stable-23_05' ``` **Cause:** Package name wrong, or Nix channel too old. **Solution:** ```nix # replit.nix — update channel and fix package names { pkgs }: { deps = [ pkgs.nodejs-20_x # not...