"Other" Folder on Windows phone filled up 99.9% of - Microsoft Community

on 1 of lumia640 phonse running on windows8.1, "other" folder has taken  99.9% of internal phone storage.
problem "other" folder there no way see files hidden inside folder , there no way tell windows8.1phone os clear "other" folder.
don't want having factory reset phone clear "other" folder.
wonder if "other" folder contains virtual memory paging files become stuck.
if "other" folder contains virtual memory file has taken 99.9% of internal storage, there way clear folder without having factory reset phone?

before say, upgrade lumia640 phone windows10mobile, have other lumia640 phone running on windows10 mobile.
compared windows8.1phone windows10mobile, windows10mobile sluggish when try use phone. when try on phone "desktop", has lot of virtual memory "....." on top of screen before os can free enough ram function properly. on windows8.1phone, it's not extreme windows10mibile in doing lot of virtual memory paging on try on phone.
between windows8.1phone , 10mobile on lumia640, opinion windows8.1phone more stable windows10mobile after using phone week or longer.

found, making phone backup microsoft cloud storage broken since january year. backup appear go 100% cannot find backup image sometime in 2016 on cloud backup.
don't know if microsoft knows these types of problems on windows phone or don't care anymore.
if knows workaround on how clear "other" folder on windows8.1phone , prevent windows10mobile tons of virtual memory paging anything, please let me know.

other on sd card contain music & video if sd card device,as storage sense not "gatekeeper" @ time allocates other.

you can check if photos , video backed upon onedrive checking onedrive app via phone, .

onedrive 5gb files not backed can copied drag & drop phone onedrive

i don't know rely on notification last backed up displayed

afterwards.

others can't deleted, there 3 areas user can remove temporary files, else more or less essential.

here earlier answer , support sheet re storage on phone.

additional 06/0317 @10.05

"other. files don't fall under category , file types phone doesn't recognize."

android has file manager, others on android phone these itemised apps , app data per app, on windows these collectively measured 1 item "others", files strange extension found here

if clear or having said on android phone did clear these files break something.

apps deleted , reinstalled may lose history

Mobile Devices / Microsoft Lumia and Nokia Lumia / Using Windows 10 on phone