Campaigns cannot be migrated from Fantasy Grounds Unity (FGU) to Fantasy Grounds Classic (FGC). It is a one-way upgrade process only.
FGU - Fantasy Grounds Unity
FGC - Fantasy Grounds (Classic)
To start with, you need to know where your FG data is stored. We will call these two locations <FGC Data> and <FGU Data>, one for classic and one for Unity.
The FGC data folder can be found from the FGC launch screen, it is the folder icon in the top right corner.
The FGU data folder can be found from the FGU launch screen, it is the folder icon in the top left corner.
Inside the Data Folder is a ‘campaigns’ sub-folder. Inside that is a folder with the names of each campaign.
While FGC and FGU are not running, copy (don’t move) the ‘<FGC Data>/campaigns/<your campaign name>’ folder to ‘<FGU Data>/campaigns/<your campaign name>’
Start FGU and Host Campaign to access your migrated campaign!
FGC Data Files Overview; https://www.fantasygrounds.com/wiki/index.php/Data_Files_Overview
FGU Data Files Overview; https://fantasygroundsunity.atlassian.net/wiki/spaces/FGCP/pages/996644323