Getting errors often in homepage.

Hi all,

I get few errors often in my opencart 2.0.1.1. But when I reload the page after sometime the error disappears. Why is it so. I get it repeatedly.

I get errors like:

PHP Warning: fread(): Length parameter must be greater than 0 in /system/library/cache/file.php on line 32

in my homepage and also in my admin panel. I get this error more often compared to the other one and it also disappears after some times automatically.

PHP Warning: imagejpeg(): gd-jpeg: JPEG library reports unrecoverable error: in /system/library/image.php on line 45

in the products edit tab. But again it disappears after some times.

Also I found when I refresh the modifications the error disappears (maybe I think)

Can somebody help me?