Multiple answers!

After finding 4 different answers I gave up:(

Pretty sure I got the body of it, but I gave up at the corners.

Ugh. Without some hint this is impossible.

Finally did it! ouf! the "cross" is only in the center!
I will give you some hints:

- You have X diagonals in the 4 (5x5) corner squares.
- You have a diagonal going from column 5 row 1 to column 10 row 6
and from column 1 row 5 to column 6 row 10
- another diagonal joins column 10 row 6 to column 6 row 10

the rest should be easier :S.

Thank you, Chano - the help was really necessary since there are soooo many possibilities...

Thank you, Chano, for the hints - now i was able to solve it!

Multiple possible solutions. Thank you for the hints, Chano.