[Q] ln command dont work on a directory with write permissions

Hi there,
I'm working with a stock, non rooted, lollipop 5.0.2 for xt1032 Moto G ROM, I'm trying to create a symbolic link from "popcorn download" folder to "my downloads" folder, so other programs can take the movies for streaming or whatever (who cares why anyways) but even when a touch or rm command works fine, ln commands doesn't like to lend a hand.

bad boy LN, bad boy. :p

Here is an exerpt on what i did:

1|u0_a135@falcon_umts:/sdcard/Download $ pwd
/sdcard/Download
u0_a135@falcon_umts:/sdcard/Download $ ls -l /sdcard/time4popcorn/downloads
drwxrwx--- 3 root 1028 4096 Apr 25 02:29 3980d0dd-29a9-4711-9a83-7955661b1aef
drwxrwx--- 3 root 1028 4096 Apr 25 02:34 3f02c279-84bb-4d74-bb69-2a7959a23774
drwxrwx--- 2 root 1028 4096 Apr 25 02:31 50548bf9-6cf6-436b-9b80-179ec8fc8bca
drwxrwx--- 3 root 1028 4096 Apr 25 02:00 c20989ae-375b-46e0-aa6e-d373c0bf2659
u0_a135@falcon_umts:/sdcard/Download $ touch popcorn
u0_a135@falcon_umts:/sdcard/Download $ ls -l
-rw-rw---- 1 root 1028 457290 Apr 24 22:29 422.pdf
drwxrwx--- 2 root 1028 4096 Apr 19 04:17 BigBang Theory
drwxrwx--- 2 root 1028 4096 Apr 19 04:12 Super_Mario_Theme
-rw-rw---- 1 root 1028 0 Apr 25 18:00 popcorn
u0_a135@falcon_umts:/sdcard/Download $ rm popcorn
u0_a135@falcon_umts:/sdcard/Download $ ln -s /sdcard/time4popcorn/downloads popcorn
ln: popcorn: Operation not permitted
1|u0_a135@falcon_umts:/sdcard/Download $ whoami
app_135
u0_a135@falcon_umts:/sdcard/Download $ id
uid=10135(app_135) gid=10135(app_135) groups=1015(sdcard_rw),1028,3003(inet),9997,50135( app_40135)
u0_a135@falcon_umts:/sdcard/Download $


I hope you can trhow some light to me and help me out
.
Thanks in advance, and kind regards to everyone! :highfive:
:cowboy: Gnokix :cowboy: