Finally! Jobar13, start in the top left corner and match the 2's and 3's in the columns and rows - hope that helps - you're looking for a distinct pattern diagnally accross the block down to the bottom right corner...
I keep coming back to this, trying to do it with fresh eyes. I try to follow the clue but always end up doing it wrong. Anyone who solved it have anymore hints to give?
Diagonally symmetrical. It's a chain with 1 partial link, 2 full links, 1 partial link from top left to bottom right. Squares on the diagonal all except 1,1 8,8 9,9 16,16 17,17 24,24 25,25 Then each 1,2,3 group forms the end of a link The first is R1,C3 R2,C2/3 R3 C1/2/3 The second is R6, C6/7/8 R7,C6/7 R8,C6 Reflect that down for each group then join the ends to make a chain. Hope that helps :-)