How to access invisible data in Windows 10 phone memory?

[Allen Minton]

My Lumia 640 LTE keeps informing me that my internal memory is almost full and that I must delete at least 100 Mb in order to allow certain apps to function. (For example, WhatsApp has stopped functioning.) However, all of the files or folders that I can examine using File Explorer are very small. There obviously must be almost 16 Gb of hidden data. How can I view and manipulate the hidden data? I would like to move as much as possible to the added 16 Gb flash memory card, which is almost empty.

 

[SAIF8897]

My Lumia 640 LTE keeps informing me that my internal memory is almost full and that I must delete at least 100 Mb in order to allow certain apps to function. (For example, WhatsApp has stopped functioning.) However, all of the files or folders that I can examine using File Explorer are very small. There obviously must be almost 16 Gb of hidden data. How can I view and manipulate the hidden data? I would like to move as much as possible to the added 16 Gb flash memory card, which is almost empty.

It is difficult at best. It is quite possibly the windows system files hogging the storage.
Try to delete whatsapp and email accounts and put them back on.

 

[anthonyng]

Have you looked in settings, system, storage? It'll break down what you have stored. Can sometimes recover a lot from temporary files
Also clear edge cache cookies temp files

It could even be your WhatsApp media clogging things

 

[skald89]

Go to storage and check the apps. Sometimes app take up a lot more space than you think. I recently reset the apps and it cleared up a bunch of space.