Same here. Updated to Xcode 15.4 (from 15.2 I believe).

Thanks a lot for the detailed explanation Kevin. For mi this is a case close.

Finder Sync Extensions seem to be exclusive, the first that applies to a directory stays and no more can be registered to that directory. Since iCloud uses its own Finder Sync Extension, no other can register there. Even worse, the first macOS 15 Sequoia beta does not run any third party Finder Sync Extension, as far as I can test.

Thanks a lot Kevin and all the team. Can confirm the option is there in the beta and works properly and even the FIFinderSyncController.showExtensionManagementInterface() brings the expected panel again.

Please close this issue since it’s fixed now and it’s going off topic.

@yjogol can confirm iOS 26 beta 9 has this fixed, tested on an iPad mini 5. Folder icons are not rendered though.

I can also confirm this is only partially fixed in iOS 26 beta 9. It still fails with the same error on some types. For example .strings files: Error returned from iconservicesagent image request: <ISTypeIcon 0x132fcec80> Type: com.apple.xcode.strings-text, Config: (null), Digest:B14B8732-EB60-3CDD-BC18-A1318AC72611 - <ISImageDescriptor: 0x132a3eda0> (220.00, 220.00)@2x v:1 l:5 a:0:0:0:0 t:0:0:0:0 s:2 ps: 0 digest: F75CCEBC-2BD0-3469-89C9-7EAC3379AB72 error: Error Domain=NSOSStatusErrorDomain Code=-609 "Client is disallowed from making such an icon request" UserInfo={NSLocalizedDescription=Client is disallowed from making such an icon request}

The biggest issue is that the QLThumbnailGenerator returns no errors and even returns a representation. So we cannot determine if the representation is valid.