[Zubersoft]

What you will need to do is to open MobileSheetsPro on your tablet, long press on a song to start selection mode, select each song you want to export (or tap the select all icon in the floating toolbar if you want to select every song) and then tap Share->Export files. Select a destination either in the cloud or on the tablet. After the export completes, copy those file to your PC using a USB cable if you created the files on the tablet itself, otherwise download the files off the cloud on your PC. You said "they simply do not get exported" - what does that mean exactly? Does that mean the files are not being generated in the destination you selected? Or are you saying the content of those files does not contain the things you added? Make sure you check all of the options on the export dialog so that the generated file contains every annotation you've created.

If you are using MobileSheets on your PC and want access to your entire library instead of just the exported files, then I would recommend creating a library backup file on your tablet under Settings->Backup and Restore->Backup Library, transferring that .msb file to your PC, then restoring it in MobileSheets on your PC under Settings->Backup and Restore->Restore Library from Backup. Then you'll have access to your entire library. You can synchronize future changes under the Sync Library->Sync to another device feature. It's best to perform one-way synchronizations, so update one device at a time to simplify things.

Mike