OTA update failed

I downloaded the OTA update and whenever I install it, it gives me this..
Finding update package...
Opening update package...
Verifying update package...
Installing update...
Verifying current system...
/dev/block/platform/msm_sdcc.1/by-name/system has been remonted R/W; reflash device to reenable OTA updates
E:Failed to install /sideload/package.zip
E: Please take note of all the above lines for reports
Installation aborted​

I searched on google but I could only find solutions which include downloading the whole rom, is there another way to fix this? I'm scared that flashing the rom might wipe my data. I already tried downloading the update thru the internet but still gave me the same thing. I'm rooted, and have the stock recovery. Thank you