Problem with ITS Template Change

All;

I am trying to change a HTML Template SAPLBBP_PDH_CUF 100 of Internet Service BBPCUF.

When i do that i get an error like " Carry out modification comparison for IATU BBPCUF 99100 SAPLBBP_PDH_CUF first. No changes possible ".

I am not able to understand the reason for this error. Any help

on this would be greatly appreciated.

Thanks!