Ebook content downloading error

I am having issue with downloading content of ebook it shows the following error :

Problem signature:   Problem Event Name: BEX   Application Name: DigitalEditions.exe   Application Version: 4.5.2.0   Application Timestamp: 57a3f6aa   Fault Module Name: StackHash_0a9e   Fault Module Version: 0.0.0.0   Fault Module Timestamp: 00000000   Exception Offset: 70612059   Exception Code: c0000005   Exception Data: 00000008   OS Version: 6.1.7601.2.1.0.256.1   Locale ID: 1033   Additional Information 1: 0a9e   Additional Information 2: 0a9e372d3b4ad19135b953a78882e789   Additional Information 3: 0a9e   Additional Information 4: 0a9e372d3b4ad19135b953a78882e789

And even while adding ebook it shows the following error :

Error getting license. License server communication problem:E_ADEPT_NO_TOKEN