After using the clear data and log off button to make some space on my sdcard, the application froze and crashed. After that the sd card wouldn't let me delete/write anything to it. Later i found out that it somehowgot mounted as read-only so i mounted it back as read write and everything works. Here's how (you need root for this):
1. Install ES File Explorer from Google Play Store
2. Slide from the left side to open the menu then tap on "Root Explorer" NOT the on/off button
3. Tap on mount r/w
4. Tick the RW dot next to external_SD
5. Tap on OK
Voilá your sdcard is back
Just a tip for people who might come across the same issue.