Jamroom 4 and Jamroom 5+ are not compatible in any way. "Upgrading" to the latest Jamroom is a multi-step process:
Create a new install of Jamroom in a different location on your server (or a completely separate server).
Download the Jamroom Import module:
https://www.jamroom.net/the-jamroom-network/networkmarket/67/jamroom-5-import
and install the Jamroom 4 module it contains in your Jamroom 4 install.
Install the Jamroom Import module in your Jamroom install via the Marketplace.
Follow the directions to "Import" your Jamroom 4 site to your new Jamroom site:
https://www.jamroom.net/the-jamroom-network/documentation/modules/868/jamroom-4-import
If you're unsure of doing this process yourself, Jamroom 4 importing is offered as a Service:
If you are wanting to import data from Jamroom 4 to Jamroom 5, see the documentation on the jrImport module here
If you are wanting to upgrade a Jamroom 5 system to a newer version of Jamroom 5 see the Howto: Upgrade Jamroom 5