how to add sandbox web part to master page in share-point 2013??

i tried so many things,followed bunch of blogs,but still i am not able to add sandbox web part to master page ,it shows me an error as bellow

ExecuteRequestInSandBox call failed. System.NullReferenceException: Object reference not set to an instance of an object.    
 at Microsoft.SharePoint.WebPartPages.BinaryWebPartSerializer.Serialize(PersonalizationScope scope, BinaryWebPartSerializerFlag binaryWebPartSerializerFlags, BinaryWebPartSerializerWriter writer)    
 at Microsoft.SharePoint.WebPartPages.BinaryWebPartSerializer.Serialize(SerializationMode mode, BinaryWebPartSerializerFlag binaryWebPartSerializerFlags, BinaryWebPartSerializerWriter writer)    
 at Microsoft.SharePoint.WebPartPages.SPUserCodeWebPart.EnsurePersistedBlobsMatchPropertiesCollection()    
 at Microsoft.SharePoint.WebPartPages.SPUserCodeWebPart.GetWebPartDataForRemoteCall(Object& viewState, Object& controlState)    
 at Microsoft.SharePoint.UserCode.SPUserCodeWebPartRemoteExecutionHelper.ExecuteRequestInSandBox(HttpContext context, SPWeb web, SPWebPartManager manager, SPUserCodeWebPart userCodeWebPart)

how can i get rid of this issue,

any help will be highly apriciated,

Thanks in advance