[Trisquel-users] GRUB error

[apvp]

I've set a password for GRUB in my desktop machine and now i can't boot  
Trisquel and i get the following error: error: png: chunk size error.
alloc magic is broken at 0x1f706670
Aborted. Press any key to exit.
If i press any key i'll just keep getting the same message.

Before this happened i had edited /etc/grub.d/00_header and placed at the  
bottom of the file the following: cat