@plasmaboy I have moved your topic to the TripleA Support forum.
404 is a “not found” code. You might have addressed a website or a server that could not be found.
Make sure you select the axisandallies.org forum instead of the triplea-game.org forum when loading the savegame and entering the PBF-mode. Also make sure to enter your correct forum name and password. Better check that each time you load a savegame.
I believe there is a help file associated with the program that you get when you download it; it’s either on the main screen or in the folder you saved TripleA to. That will have all the help you need.