Internal memory (sdcard0) not writable - Android 4.3 - Xperia T (LT30p) After a bootloop that I experienced after messing around with Android, I flashed a stock ROM to my LT30p using FlashTool. 

Everything went smoothly, except for the fact that I can't create files in the internal memory (/storage/sdcard0) with any file explorer. This includes trying to download files from browsers, they fail instantly. So I figured it's a read-only situation going on.

I also flashed another stock ROM, clearing all data, but the problem persisted.

The funny part is that the mount command gives me this:

rootfs / rootfs rw,relatime 0 0
tmpfs /dev tmpfs rw,seclabel,nosuid,relatime,mode=755 0 0
devpts /dev/pts devpts rw,seclabel,relatime,mode=600 0 0
none /dev/cpuctl cgroup rw,relatime,cpu 0 0
proc /proc proc rw,relatime 0 0
sysfs /sys sysfs rw,seclabel,relatime 0 0
selinuxfs /sys/fs/selinux selinuxfs rw,relatime 0 0
debugfs /sys/kernel/debug debugfs rw,relatime 0 0
none /acct cgroup rw,relatime,cpuacct 0 0
tmpfs /mnt/secure tmpfs rw,seclabel,relatime,mode=700 0 0
tmpfs /mnt/asec tmpfs rw,seclabel,relatime,mode=755,gid=1000 0 0
tmpfs /mnt/obb tmpfs rw,seclabel,relatime,mode=755,gid=1000 0 0
/dev/block/platform/msm_sdcc.1/by-name/System /system ext4 ro,seclabel,relatime,
discard,data=ordered 0 0
/dev/block/platform/msm_sdcc.1/by-name/Userdata /data ext4 rw,seclabel,nosuid,no
dev,noatime,discard,noauto_da_alloc,data=ordered 0 0
/dev/block/platform/msm_sdcc.1/by-name/Cache /cache ext4 rw,seclabel,nosuid,node
v,noatime,discard,data=ordered 0 0
/dev/block/platform/msm_sdcc.1/by-name/SDCard /mnt/int_storage ext4 rw,seclabel,
nosuid,nodev,relatime,discard,noauto_da_alloc,data=ordered 0 0
/dev/block/platform/msm_sdcc.1/by-name/apps_log /mnt/idd ext4 rw,seclabel,nosuid
,nodev,noexec,noatime,discard,nobarrier,data=ordered 0 0
/dev/fuse /storage/sdcard0 fuse rw,nosuid,nodev,noexec,relatime,user_id=2800,gro
up_id=2800,default_permissions,allow_other,allow_utime_grp 0 0


so, from this

/dev/block/platform/msm_sdcc.1/by-name/SDCard /mnt/int_storage ext4 rw,seclabel,
    nosuid,nodev,relatime,discard,noauto_da_alloc,data=ordered 0 0


I conclude that I should be able to create files/folders as normal (since it says rw). 

What am I missing? I googled this in many ways but to no avail. 

Thank you for any help in advance!

PS. Phone is rooted, of course.
I finally fixed it. In case someone has the same problem in the future, here's what I did:


After googling here and there about how to completely wipe an Android phone, I read that to do that you must encrypt your data first and then do a factory reset.


So, I still don't know what caused it, I only know that now it's fixed.