angular/angular · error · SwCriticalError

Failed to update the caches for request to '${req.url}' (fet

Error message

Failed to update the caches for request to '${req.url}' (fetchAndCacheOnce): ${errorToString(err)}

What it means

After a successful fetch, the service worker writes the response into CacheStorage and its metadata into IndexedDB; if that write throws — the code comment cites 'Entry was not found' when the user cleared all data via DevTools while the SW was still running and serving another tab — the SW can no longer work correctly and throws SwCriticalError (the situation is unrecoverable for that SW instance). The Driver falls back to a safe network fetch for the current request.

Source

Thrown at packages/service-worker/worker/src/assets.ts:353

        const cache = await this.cache;
        await cache.put(req, res.clone());

        // If the request is not hashed, update its metadata, especially the timestamp. This is
        // needed for future determination of whether this cached response is stale or not.
        if (!this.hashes.has(this.adapter.normalizeUrl(req.url))) {
          // Metadata is tracked for requests that are unhashed.
          const meta: UrlMetadata = {ts: this.adapter.time, used};
          const metaTable = await this.metadata;
          await metaTable.write(req.url, meta);
        }

        return res;
      } catch (err) {
        // Among other cases, this can happen when the user clears all data through the DevTools,
        // but the SW is still running and serving another tab. In that case, trying to write to the
        // caches throws an `Entry was not found` error.
        // If this happens the SW can no longer work correctly. This situation is unrecoverable.
        throw new SwCriticalError(
          `Failed to update the caches for request to '${
            req.url
          }' (fetchAndCacheOnce): ${errorToString(err)}`,
        );
      }
    } finally {
      // Finally, it can be removed from `inFlightRequests`. This might result in a double-remove
      // if some other chain was already making this request too, but that won't hurt anything.
      this.inFlightRequests.delete(req.url);
    }
  }

  protected async fetchFromNetwork(req: Request, redirectLimit: number = 3): Promise<Response> {
    // Make a cache-busted request for the resource.
    const res = await this.cacheBustedFetchFromNetwork(req);

    // Check for redirected responses, and follow the redirects.
    if ((res as any)['redirected'] && !!res.url) {

View on GitHub (pinned to 51cb07e980)

Solutions

1. Unregister the service worker and reload to force a clean install: navigator.serviceWorker.getRegistrations().then(rs => rs.forEach(r => r.unregister())).
2. When clearing storage intentionally, close all app tabs first so no SW survives to observe the wipe.
3. Ship a new app version so existing clients pick up a fresh SW with rebuilt caches.

When it happens

Trigger: cache.put() or the metadata-table write rejecting inside fetchAndCacheOnce: site data cleared while the SW stays alive in another tab, storage eviction under quota pressure, or browser storage corruption.

Common situations: 'Clear site data' clicked in DevTools with the PWA open in another window/tab; iOS/Safari aggressive storage eviction; low-disk devices where the browser revokes storage.

Related errors

• Cache is throwing while looking for a match: ${error}
• Not a valid duration: ${match}
• Not a valid duration unit: ${res[2]}
• Asset-group '${group.name}' in 'ngsw-config.json' uses the '
• SERVICE_WORKER_DISABLED_OR_NOT_SUPPORTED_BY_THIS_BROWSER

AI-assisted analysis of angular/angular@51cb07e980 (2026-08-22). Data as JSON: /api/errors/928857924d0d4609. Report an issue: GitHub.