TL;DR: Run all NL programs as Admin!
Windows 8 and 10 do this thing with some programs that do not have the required administrator rights to access the C: drive where new and altered files are not allowed in the folders on the C: drive that they need to be in, and they are shunted to this folder:
Code:
C:\Users\YOURNAME\AppData\Local\VirtualStore
This provides a level of safety from malware, but makes doing stuff with DFBHDTS and the MEd a pain in the ass 'til you grant the .exes admin rights.
Maybe something like this is happening with your JO BMS2MIS?
Start Windows Explorer, click the View menu, open the Show/Hide tab, and activate the "Show hidden elements" checkbox so you can see the AppData folder. Then go to the VirtualStore folder at the URL above, see if there's a Programs (x86) folder, then see if there's a Novalogic folder, and so on 'til you maybe find the .mis and .bms files. Drag those out of the
virtual game folder and drop those into the
actual game folder.
My SOP with all NovaLogic programs — installers, mission editors, and games — right-click the .exe or the start icon, click Properties, select the Compatibility tab, and confirm the checkbox "Run as Administrator" is activated.
If this is not what's happening on your crate, well, I've shared a bit of knowledge that might be helpful to somebody at some point.
And really, what's better than being helpful to somebody at some point?