Log broken with [...]

I use the syslog for send log from my fortigate to external server.

In the web log, in the some case, i've the field url broken witch [...] (ex. url="/hphotos-xpt1/t51.2885-15/s240x240/e35/c142.0.7[style="background-color: #ffff00;"][...][/style]/11255300_1654532498164416_1675388327_n.jpg")

This it's a proble of fortigate or other.

Thank