Suddenly a strange issue appeared in the WordPress Theme-Editor page. The Update File button at the bottom changes its position up and down when I try to click it! The issue is present no matter what theme is active.
I have inspected the button and found that when I disable this css it will work fine (load-styles.php):
.wp-core-ui p .button {vertical-align: baseline;}
Any idea why is this happening and how to fix it?
Thanks