NW-A45 Walkman - missing new tracks and playlists

[marukomu]

I've been using my A45 for a few years now and it has been totally fine in terms of transferring things from my laptop to the Walkman. However, I have recently encountered a couple of issues:

1. I sync the Walkman (from Musicbee, which is what I've always used) with the SD card in the laptop (again, this is the method I have always used) but when I put the SD card back in the Walkman it doesn't have any of the new tracks. I then need to rebuild the database from the reset menu, at which point the new tracks then appear. It's a pain as rebuilding the database takes ages (lots of tracks to rebuild).

2. Again when syncing the playlists are not transferring, even after rebuilding the database. I have tried limiting the number of playlists e.g. unticking them all and then just transferring 1 or 2 of them but still the same issue. 

I haven't changed anything else in the way I am using the Walkman or doing the syncing so it's all a bit strange. Anyone got any tips for this sort of thing?

Thanks!

[marukomu]

OK, let me try with another card.

I downloaded music centre but the importing of my library was such a mess that it would take forever to get it back to the way I've built up over the years with musicbee. 

[marukomu]

Ok, so I've finally managed to try out a new card and the issue is the same - playlists not copying over and some files not present, despite being synced to the card. 

I've also done a factory reset on the device but still no joy. I really do think the only thing this can be is that there is an inbuilt maximum number of folders that the device can handle. Does anyone know if this is the case and whether the device can be upgraded to overcome this? I'm currently in about 995 folders.