Failed to acquire token silently. Call method AcquireToken not working

Question

    // constructor
    public ADALTokenCache(string user)
    {
        // associate the cache to the current user of the web app
        User = user;
        this.AfterAccess = AfterAccessNotification;
        this.BeforeAccess = BeforeAccessNotification;
        this.BeforeWrite = BeforeWriteNotification;

        // look up the entry in the DB
        Cache = db.UserTokenCacheList.FirstOrDefault(c => c.webUserUniqueId == User);
        // place the entry in memory
        this.Deserialize((Cache == null) ? null : Cache.cacheBits);
    }

    // clean up the DB
    public override void Clear()
    {
        base.Clear();
        foreach (var cacheEntry in db.UserTokenCacheList)
            db.UserTokenCacheList.Remove(cacheEntry);
        db.SaveChanges();
    }

    // Notification raised before ADAL accesses the cache.
    // This is your chance to update the in-memory copy from the DB, if the in-memory version is stale
    void BeforeAccessNotification(TokenCacheNotificationArgs args)
    {
        if (Cache == null)
        {
            // first time access
            Cache = db.UserTokenCacheList.FirstOrDefault(c => c.webUserUniqueId == User);
        }
        else
        {   // retrieve last write from the DB
            var status = from e in db.UserTokenCacheList
                         where (e.webUserUniqueId == User)
                         select new
                         {
                             LastWrite = e.LastWrite
                         };
            // if the in-memory copy is older than the persistent copy
            if (status.First().LastWrite > Cache.LastWrite)
            //// read from from storage, update in-memory copy
            {
                Cache = db.UserTokenCacheList.FirstOrDefault(c => c.webUserUniqueId == User);
            }
        }
        this.Deserialize((Cache == null) ? null : Cache.cacheBits);
    }

    // Notification raised after ADAL accessed the cache.
    // If the HasStateChanged flag is set, ADAL changed the content of the cache
    void AfterAccessNotification(TokenCacheNotificationArgs args)
    {
        // if state changed
        if (this.HasStateChanged)
        {
            Cache = new UserTokenCache
            {
                webUserUniqueId = User,
                cacheBits = this.Serialize(),
                LastWrite = DateTime.Now
            };
            //// update the DB and the lastwrite                
            db.Entry(Cache).State = Cache.UserTokenCacheId == 0 ? EntityState.Added : EntityState.Modified;
            db.SaveChanges();
            this.HasStateChanged = true;
        }
    }

    void BeforeWriteNotification(TokenCacheNotificationArgs args)
    {
        // if you want to ensure that no concurrent write take place, use this notification to place a lock on the entry
    }

This is my code for manage AdalToken Cache I got the following exception Failed to acquire token silently. Call method AcquireToken

got this exception in following code near to var authResultDisc

//SharePoint connection to get List Items

DiscoveryClient discClient = new DiscoveryClient(SettingsHelper.DiscoveryServiceEndpointUri,
 async () =>
 {
   var authResultDisc = await authContext.AcquireTokenSilentAsync(SettingsHelper.DiscoveryServiceResourceId, new ClientCredential(SettingsHelper.ClientId, SettingsHelper.AppKey), new UserIdentifier(userObjectId, UserIdentifierType.UniqueId));
             return authResultDisc.AccessToken;
                            });

                            var dcr = await discClient.DiscoverCapabilityAsync("RootSite");

my thinking on this is that, it dose not clearing the database entries.

Can any one help me to solve this error.

Answer 1

This is an expected exception if the access token is not able to find in the cache and refresh the access token failed. Please check whether whether you acquire the access token before you call this function.