HTTP File Upload is not working

Hello, I’m trying to upload / download files via Openfire, but I’m facing a critical problem.
I installed HTTP File Upload Plugin and tried to file transfer,
Small size files worked fine but huge (about over 50kib) files haven’t worked.

And when I check Android Client(Conversation) logcat, It says unexpected end of stream on

iOS Client(Siskin.IM) also like that (Connection lost, -1005 error)
Please give me a solution if you know!
Thank you