However people always find a way to solve problem, although the solution may not be super perfectly.
I recently update File Expert and find it restored the ability to manage external SD card.
Download app from Google Play and open to start. I notice my external SD Card is shown under Folder Tab.External SD Card is accessible and writable again in File Expert. Click to enter, choose a file and try all basic file operations, create, copy, cut, paste, rename, delete, edit and zip file within external SD card. File Expert completes all without any error.
You can even explore more available actions for External SD Card in File Expert. Like trying move a file from internal storage to SD card, sharing files on external sdcard with FTP, Web PC Suite it will be done perfectly, without any error.
What file manager do you use right now? Or is there any file manager can do more?