Unable to write to sd card after marshmallow update

Hello all, I flashed the marshmallow update on my infinix x510 .... And for obvious reasons... Applications can't access my SD card... All installed apps go to the internal storage of my device....
How do I fix this please..... I've done a reset and it didn't fix it.....

from xda-developers http://ift.tt/2bKWi90
via IFTTT