I Need Feature For Multiple User To Upload File At The Same Time

[Willy The Wizard]

Hello everyone,

I have an application where a lot of users was logged in, and they could upload a file at the same time. When I tried using gwtupload multiuploader and singleuploader, it will give me an error : The request has been rejected because the server is already receiving another file. 

Is there any way I could do multiple user upload file? It's not funny to tell my user that they have to wait for other user to finish their upload session first right?

Thanks and regards.