MCU room not allowing to share files, file upload limit set to unlimited via system properties

I am facing issue with file sharing in MCU room. I can share file in One to One chat but the issue appearing when I am trying to share file in MCU room.
File sharing size limited increased to Unlimited via system properties but the issue still appearing.
I already made Room Persistent.
While testing with Conversation app, I found the error message “You are not in the room”. Room Occupant section of OF Admin console not showing the user ID. How to make chatroom user persistent?

I need help.

You seem to have trouble in various areas. I’d suggest that you start by reading up on the group chat protocol that is implemented in Openfire. It is called MUC (not MCU) and is described on https://xmpp.org/extensions/xep-0045.html

To share files, most clients nowadays use another protocol called HTTP File Upload, which is described in https://xmpp.org/extensions/xep-0363.html

Openfire does support XEP-0363, but you need to install a plugin (called the HTTP File Upload plugin).

Thanks for the reply. Sorry, I typed it wrong.

I am already using HTTP File Upload and updated the limit via system properties. After running couple of tests I found the following -
When user trying to send file/image and accessing Gallery (i.e. - to share image) it’s kicking the user out from Occupant list, which I noticed by observing Chatroom Occupants. However the room still exist as I made them Persistent via API call.

****** Every time I tried to share a file and access Gallery XMPP kicked the user out seems user left the chatroom (according to the rules of XMPP), once I select the file and hit the share button the client app try to share it and return “failed” status, that time I can’t even send chat message.
But the App showing “Joining the Chat” message after sometime and users start to appear in Occupant Listing in Openfire, after that I can send message but file sharing still not possible as user have to leave the room to access gallery to select the file.

Seems I have to handle the presence of the user from client app, is it?
or
There’s something I can do and adjust this in openfire?

Finally found the issue that causing problem with HTTP File sharing. I tried to control the Presence so the user goes Offline, it works with Push notification service.
Accessing the image/file from gallery actually sending the app background which eventually killing the presence and kicking the user out from MUC Room. So users were unable to share file or send Chat message until they join the room again. By handling that part fixed the problem.