I am having exactly the same problem since a recent major update to my Windows 10 desktop PC, which necessitated reinstalling all my e-Sword software and modules. Everything works except my .mapx files. The system (i.e. both the Module Downloader and the Graphics Viewer) recognizes that they are loaded, displays information about each module and the Graphics Viewer lists each individual map in the file: but the main display area remains stubbornly blank! Yet the version of e-Sword on my laptop displays graphics quite happily. I have compared the files in the program directories - and they contain exactly the same files, even down to the date stamps. The Resources and User Files locations are the same ( c:\program files (x86)\e-sword\ and c:\users\MyUsername\documents\e-sword\ ); though in both cases the abs.mapx file has actually been loaded to c:\Users\MyUsername\AppData\Local\VirtualStore\Program Files (x86)\e-Sword.
I have tried repairing the installation; de-installing and re-installing; de-installing, deleting the program and VirtualStore directories and then re-installing. Still the problem persists; leading me to suspect that it must lie somewhere in the Windows registry. But where? Is there a procedure for safely cleaning the registry? I've tried using the Help/Reset e-Sword Settings option: but that didn't fix it.
One further clue, maybe. I've discovered that, as soon as the Graphics viewer is opened, it creates a file, ''c:\users\MyUsername\documents\e-sword\temp.pic". But this file is never populated; always showing 0 KB file size, and the timestamp is never updated again, even if e-Sword has been shut down, unless it is deleted while e-Sword is closed.