You are not using Webcenter UCM and ADF? In this case you are in the wrong forum.
Or do you use an ADF application to upload a file to the ucm server?
Or download a file from UCM and use the ADF app to send the file to the client?
Can you load files up to 2 GB or not?
Please give us more information and don't forget your jdev version.
We are using Webcenter UCM and using RIDC API to upload file in UCM and I am able to upload some files. Today late in the evening we found issue with disk space (IOException – No space left on the device). So it may be problem with disk space and I may fount it tomorrow or depends on our infrastructure team.
We are using ADF and Webcenter but as ADF not supporting multiple file upload we are using http://blueimp.github.com/jQuery-File-Upload/ (we are using Jdev 11.1.5)