[Constructor theme] page.php not writeable

Hi,

Yesterday I’ve updated the Constructor theme to 1.6.5

The .php and .css weren’t writable anymore so I changed permissions.
I can edit/save most of the .php’s and stylesheet, but I can’t make page.php and single.php writable.
I’ve tried to 777, 666, 767, 664, but nothing seems to work for those two php’s.

Can someone please help me out with this problem?
Many thanks in advance!