Before downloading: check your device and existing setup
The operating system, processor architecture and package format must all match. x64 and AMD64 usually mean the same desktop instruction set and don’t require an AMD processor; ARM64 is a different architecture. A file downloading successfully doesn’t mean your device can run it. For older systems without confirmed support, check the app requirements rather than relying on archived software as a long-term solution.
Before switching clients, note your subscription URL and export local overrides, custom rules and policy group settings. Generic subscription content may be reusable, but client-specific scripts, interface preferences and configuration directories may not be. Before uninstalling, make sure you can read the backup. Don’t leave your only copy of a configuration in an app directory you’re about to remove.
After installation: import, select, connect and verify
Open the “Subscription” or “Configuration” page, paste the full URL and import it. Once downloaded, select that configuration, choose an available outbound option in the policy groups, then enable the system proxy. Check that your browser can reach the sites you expect, and that sites meant to connect directly still do. Don’t rely on the tray icon alone to confirm a working connection.
TUN isn’t required on first launch. Enable it only if you need to route apps that don’t use the system proxy, and check service permissions, the virtual network adapter and DNS settings. System proxy and TUN work differently. If you’re also using another VPN or network filter, check for routing and DNS conflicts.
When something fails: save the details and change less
For an installation failure, save the installer’s exact error. For a startup failure, check the client logs. For a subscription failure, verify the URL and service status. Each issue has a different fix. If the download hasn’t finished, check the browser’s download list and available disk space. If the app starts but can’t connect, downloading it again usually won’t fix a rule or subscription issue.
Before sharing logs, hide identifying parameters in subscription URLs, node credentials and external controller keys. The error type, steps to reproduce and operating system version are usually enough for initial troubleshooting. See the Clash setup guide for the full walkthrough, or use the Troubleshooting guide to find help by symptom.