Default Having problem with my S4 and need help .

Hi , recently i switched from samsung galaxy s3 I9300 to samsung galaxy s4 I9500and i've been experiencing some really annoying problems.First of all i can't download any file from my browsers except the stock one . Every time i try to download a file the download simply fails telling me i don't have enough space available ( at least this is what Dolphin browser tells me ) , when in fact i have 6.73 GB free on my device storage and 3.66 GB free on my SD card . The second problem is that whenever i open the tumblr app or the instagram one , the images don't load up , while posts do. My device is rooted and is running on Kitkat 4.4.2. Does anybody know what's going on ?