(I'm not going to call them problems anymore).
I've upgraded to 1.3.1 and get this message on the admin page on my laptop and web host installations:
Block site_main_menu: c:\program files\easyphp1-7\www\moodle/blocks/site_main_menu/block_site_main_menu.php was not readable
site_main_menu: This folder is readable on both sites.
block_site_main_menu.php: this file is not present