[palosanto]

The folder mapping has to be set on both devices. It's discussed a bit in the tutorial video on the website when using the library sync feature. Basically, you create a name/folder pairing on each device. So for example, if you mapped this path on Android

name: composerA
path: /storage/emulated/0/MobileSheets/ComposerA

to this path on Windows:

name: composerA
path: C:\MobileSheets\ComposerA

anytime the sync encounters a file path on Android where the containing folder is /storage/emulated/0/MobileSheets/ComposerA, it will replace the folder path with Windows C:\MobileSheets\ComposerA (it finds a match for the folder path, then uses the associated name to find a matching name on the Windows folder mapping and uses the folder for that name). 

Every file/folder on Windows has to be under the storage location, so don't try to map to folders outside the storage location (that won't work). Also, based on your description, you may need to map every composer folder between the two because MobileSheets does not do a partial replacement on the path. It's replacing one folder path with another, and it must be a complete match.

I really do think that if you need this to work across platforms, you are better off having every file/folder under the storage location even if MobileSheets isn't managing your files. It will then store relative file paths instead of absolute, and this enables you to just copy the database over to Windows. It will also probably result in the folders being properly recreated on Windows without you having to take extra steps like this.

Mike

Thanks Mike,
Being a new windows laptop, I tried making a backup from the Lumi and restored on Windows and it worked.  I had set the paths first as: 
 /storage/emulated/0/MSP songs in android  and D:\MSP songs in Windows (still empty). 

I'll experiment with the sync next time as it seems a bit more involved. I use backup/restore in most occasions anyway.  
Juan