Download button not enabled

I am using Vault 4.0 version 30 day trial.
If you create a Vault as below, the download button is not activated even if you hover your mouse over the file list.
Is the 30-day trial not able to use the download function?
Please let me know if there is anything wrong with my source below.

testVault = new dhx.Vault(docLayout.getCell("d"), {
	    uploader: {
	        target: CONTEXT_PATH+"file/uploadFile?path="+FILE_TEMP_DIR+"&temp=1"
	    }
	    , downloadURL: CONTEXT_PATH+"file/downloadFile?path="+FILE_TEMP_DIR+"&name=temp_data.xlsx"
	    , customScroll: true
	});

Unfortunately, I was not able to reproduce your issue locally.
Could you please, provide a complete demo, where the problem could be reconstructed.