Hi,
Check to see if the Download Manager App is enabled.
Not sure where it is in your phone but usually you find it in Menu > Settings > Apps
Swipe to ALL APPS. Scroll down and look for "Download Manager". You may have to scroll all the way down. The apps are listed alphabetically, enabled first, then disabled
Tap on it to enter.
If there is a tab to enable it - it means that it is disabled, click to enable.
If it is already enabled
1. Disable it
2. Clear its data
3. Reboot
4. Enable it again
5. Reboot.