Customize search on express object breaks the site!

I am using Concrete 9.4.7, just upgraded to see if it fixed this issue (it didn’t). Also PHP 8.5.0RC5

I have a very simple Express object, and when I go to Customise the Search/Listing, and make any changes there, the whole system fails with an error page - with the main error being:

Call to a member function setValue() on null

Pointing to file:/var/www/concrete/src/Attribute/Category/AbstractCategory.php:171
Line is:
return $this->getAttributeKeyRepository()->findOneBy(

I first tried this on a complex object, but now on one with only 3 attributes. The issue affects all 3 sites in the multi-site, so is a rather serious result from clicking a single checkbox!

I have got the system back by removing the custom result_column from the database, but figuring out which table changed last and guessing what default would be from looking at other entries…

update ExpressEntities set result_column_set = ‘N;’ where handle=‘int_event’;

I would like to be able to modify the search/listing however. Has anyone else seen this issue?

Thanks,

Steve