I have found it impossible to upgrade from CiviCRM 5.25 to 5.28 to get around the breakage caused by the WP upgrade from 5.4 to 5.5
My attempted solution has been to make a staging site, completely remove civiCRM and reinstall using the 5.28.3 zip file. All seems to go well including adding the UK i10n files until I go to /wp-admin/options-general.php?page=civicrm-install
Where I get the message Sorry, you are not allowed to access this page.
As the only admin on the site, I find this strange. Any hints?