Can NOT find LSCWP path for object cache initialization

please try enable and disable object cache, or vice versa , disable then enable it.

@andrew55 is file created in: /mysitepath/wp-content/object-cache.php ?

it should be like 644 permission on that file

@andrew55 Let’s try this:
in site folder wp-content please add file test.php
with content:

<?php
ini_set('display_errors', '1');
ini_set('display_startup_errors', '1');
error_reporting(E_ALL);
file_put_contents('test.log', 'test QC');

Visit: your_site.com/wp-content/test.php and observe what happens. Please replace your_site.com with your site link.

If you see file test.log (in same folder) it means that we need to look why LSC cannot write there.
But if error or no file present, then it’s about owner and permissions from parent folder or current one.