During Save as pdf custom report throw following error.
Unable to connect to the remote server at Microsoft.WindowsAzure.Storage.Core.Executor.Executor.ExecuteSync[T](RESTCommand`1 cmd, IRetryPolicy policy, OperationContext operationContext) at Microsoft.WindowsAzure.Storage.Table.CloudTable.Exists(Boolean primaryOnly, TableRequestOptions requestOptions, OperationContext operationContext) at Microsoft.WindowsAzure.Storage.Table.CloudTable.CreateIfNotExists(TableRequestOptions requestOptions, OperationContext operationContext) at Microsoft.DynamicsOnline.Infrastructure.Components.TableAccessor.TableStorageAccessor.PerformOperation(CloudStorageAccount storageAccount, String tableName, Func`1 operation) at Microsoft.DynamicsOnline.Infrastructure.Components.TableAccessor.TableStorageAccessor.AddRecord[T](CloudStorageAccount storageAccount, String tableName, T record) at Microsoft.DynamicsOnline.Infrastructure.Components.SharedServiceUnitStorage.SharedServiceUnitStorage.UploadData(SharedServiceUnitStorageData data, Stream stream) at
It was problem that Azure Storage emulator was not running on my machine.
For this I have to open window start and write there Azure Storage emulator.
After it searched, click and run the Azure storage Emulator.
In my Case emulator Version was out date. I have to download it from Microsoft Cloud. After running that service. Issue was resolved. Report successfully download as pdf.
Reference : https://docs.microsoft.com/en-us/azure/storage/common/storage-use-emulator