accessCheck() should be performed on entity queries, but the method does not exist in search_api queries.
I'm just amazed how long this bug has been introduced (11 months) since it breaks the module. See https://git.drupalcode.org/project/search_overrides/-/commit/07ae712ed37518cae1cbccdf2abe47621f25efdf#fe0f1055e0a8d3c324dc26e1369441c782005519_89_89.
Install search_overrides
On /admin/config/search/search_override/add try to autocomplete promoted content. The autocomplete doesn't work and the console show a 500 error: Error: Call to undefined method Drupal\search_api\Query\Query::accessCheck() in Drupal\search_overrides\Controller\Manager->searchIndexes() (line 89)
Remove the accessCheck() call on line 89 in Drupal\search_overrides\Controller\Manager.
Fixed
2.1
Code
Thanks for identifying this, and for suggesting a fix. I have to assume that this wasn't identified earlier because it requires configuring the module in a specific way that is not the default.
Merged in.
Automatically closed - issue fixed for 2 weeks with no activity.