To save your work, click on the « Save » button, the third button from the top-right side of the screen.
The files are located under My Documents/Tactic3D/tactics under Windows system, and under the folder MyUser/Library/Tactic3D/ tactics under MacOS. Caution : the folder Library is hidden on Mac by default by Apple, if you want to access to this folder, search on the internet, it’s easy to find the manipulation to show it. The only reason you have to access to the files stored on your harddisk, it’s to copy and send the tactics files to your colleagues. WARNING : they must have the same license, otherwise they cannot read your files, it’s a security feature.