What Happens If a License Server Goes Down?

It's a fair question to ask before you depend on any licensing vendor: what happens to your customers' apps during a brief outage, an extended one, or if the vendor disappears entirely? These are three genuinely different failure modes, and a serious answer treats them separately rather than waving at "high availability" and moving on.

Layer 1: a brief network blip

The most common case by far is a flaky connection, not a real outage — a customer's Wi-Fi drops for ten seconds while your app happens to call validate(). This shouldn't be a special case an app has to handle explicitly. With offline grace configured on the license and a usable signed result already cached, PermitCore's SDKs can use that cache on a connection failure until its signed deadline:

catch (Exception ex) when (ex is HttpRequestException or TaskCanceledException)
{
    // Server unreachable — fall back to the last cached result
    return TryLoadFromCache(licenseKey) ?? new LicenseResult
    {
        IsValid   = false,
        Message   = "Cannot reach license server.",
        IsOffline = true
    };
}

This is the real code from PermitCore's .NET SDK — a bad network moment does not automatically mean a locked-out customer.

Layer 2: extended, expected disconnection

Some apps need to run offline by design — an air-gapped terminal, a laptop that's disconnected more often than not. That's a different problem from a transient blip and needs a different mechanism: a deliberately signed offline token (ECDSA P-256), issued once while online, cached, and verified entirely on-device with no server call for as long as the token's grace period allows. See our offline grace mode and offline validation posts for exactly how this works and what it honestly can't protect against (a hostile local clock, mainly).

Layer 3: what if the vendor itself goes away?

This is the question that actually matters for a purchasing decision, and it's the one vendors talk about least. If a licensing vendor shuts down entirely, what happens to software you've already shipped to customers? Already-issued offline tokens can be verified with a trusted public key shipped in the app until their signed expiry. Token generation currently accepts 1–365 days; a perpetual license does not make its token permanent. Signing-key export on all plans and Enterprise self-hosting support a separately operated continuity solution, with its own protected keys, backups and tested deployment. Plan for reinstalls and replacement devices too. See our ownership and shutdown planning guide for a final-build and end-of-life checklist.

What to actually check before you commit to a vendor

Ask specifically: does a routine network blip fail closed or gracefully degrade? Is there a real mechanism for extended offline use, not just a marketing claim? And critically — is there any continuity plan if the vendor itself stops operating, or does every customer's license silently stop working the day the company does? The honest answer for most licensing services is "we haven't thought that far," which is worth knowing before you build a business on top of one.