Default [ROOT] Samsung Galaxy Mega, not reading SD card after root


I have recently rooted my galaxy mega dual sim phone. Everything seemed ok, until I realized my SD card is not shown in storage section. It seems my phone no longer detects my SD card.

I found a really similar problem posted in the forums, but the instructions were for s4 mini... Anyhow I copy/paste what the op had said there:

Since I rooted my phone the device won't mount my SD card. As soon as I boot the device it shows a system notification "You can safely remove SD card".
When I go into Settings>More>Storage the bottom option is for "Mount SD card". However when I press this it says "Preparing SD card" and then roughly 10 seconds later says "SD card safe to remove".

I have been using the Sandisk 64GB XC I SD card with the phone since I bought it.

The phone seems to have rooted correctly. Rootchecker advises that the phone is properly rooted.
I`m pretty sure, It is not hardware related, because I can see my SD card in recovery mode, and my pc seems to be able to read it just fine.I am also able to use other SD cards on my phone ( I tested a 16GB and a 4GB) but not the mentioned SD card ( 64GB ).

What do you think the problem is? Is it kernel related? If so, what kernel should I use to fix it?