Subscription not imported, or no servers after an update
Start with the specific error reported by the subscription update. A retrieval failure is different from a content parsing failure. For a retrieval failure, check the device's basic network connection, the complete URL, and subscription access permissions. For a parsing failure, confirm that the returned content is server information the app can recognize, not a login page, expiry notice, or ordinary webpage. If the update succeeds but there are no usable entries, check for filters and whether the subscription contains active servers.
Do not paste a complete subscription URL containing credentials into a public testing service. To check subscription status, use the account page for your service or describe the error to the original service provider. Keep existing entries and check or update them first rather than deleting everything and adding it again.
Server added, but the connection fails or disconnects immediately
Reopen the server editor and check Type, Host, Port, and authentication details. If using TLS or a specific transport, also check related fields such as the server name and path. Use your existing information rather than guessing. Confirm that the device time is correct, then check whether the current network allows access to the address and port. Correct parameters do not guarantee that the server is online; contact the original service provider if needed.
If system authorization is incomplete, resolve that first instead of changing the server password. If another automatic connection behavior changes the connection as soon as it starts, check On Demand in Settings and consider the status of other VPN configurations on the system. Complete a manual connection check first, then configure on-demand connection conditions.
Connectivity Test fails, but some destinations work
Open Test Method in Settings and confirm that the selected method is appropriate for what you want to check. A test that gets no response does not necessarily mean webpage requests will fail; likewise, a successful test does not prove that authentication, DNS, and the destination service are all working. Keep the server and mode unchanged, cross-check with another destination you actually need, and then decide whether to adjust the test settings.
Connected, but a destination will not open or routing is unexpected
First distinguish DNS resolution failures, connection timeouts, authentication errors, and errors returned by the destination service. If you suspect DNS, note the current values, then use the Settings reference to check how system DNS, custom DNS, and rules work together. Do not add multiple DNS addresses from unknown sources at once. If Proxy works but Config does not, check whether Rule matches REJECT too early, routes to DIRECT unexpectedly, or references a missing policy.
Keep a copy of the original configuration before changing rules. After editing, establish the relevant request again and check what matched. DOMAIN-SUFFIX and DOMAIN-KEYWORD have different matching scopes, while IP-CIDR matches addresses; do not infer their behavior from rule names alone. To review the basics, see the rule keyword glossary before editing the configuration.
Prepare diagnostic information that can be checked
Diagnostics in Settings can be used as a starting point; available options depend on the current interface. Record the mode, server protocol, network in use, failed step, and exact error message. Before sharing logs, check for addresses, authentication details, and subscription parameters, and remove sensitive information. “A domain times out in Config but works in Proxy” is more useful for troubleshooting than simply saying “it does not work.”
Step complete when: You can identify whether the issue is with importing, authorization, the server, DNS, or rules, and have recorded the relevant observations. If the connection is restored, return to your usual settings one at a time rather than treating a temporary troubleshooting mode as the final configuration.