WP Error and Outdate Theme

I am getting the following error on my WordPress dashboard:
Background updates are not working as expected: Error Some files are not writable by WordPress:
wp-load.php

We are running WordPress v5.62. I contacted our host (Bluehost) and they said the issue is with a theme file and they could not help beyond that. We are running Highend 3.5.0.1, which I realize now is outdated (I am not well-versed in websites). Could these be related? If I update the theme to an updated version could it resolve the error? We are also not able to access our Highend options (get into layout options, etc). I’ve read that updating our theme could help with this issue, but should I be concerned updating from such an old version?