Ok, it seems that the limit being exceeded was for the whole session and not per request/prompt. Misunderstanding on my part. Disregard.

Filed FB16023451 though details are scant since only a couple of people have reported this so far. My app does not define a sidebar icon but if I add one, it does show up.

Icons are the generic document icon (page with bent corner). User says that after a Finder restart, all the icons are ok except for one (which one seems to change) which changes after a few seconds. Dragging a file over any of the icons changes them to a generic icon as well.

User reports that it's being replaced with a generic document icon. They claim it's everything in the sidebar. I'll see if they can provide a screenshot.

To clarify, I realize I'm using things out of their recommended context, as mentioned in this thread here: https://developer.apple.com/forums/thread/756711?answerId=806555022#806555022

I'm basically monitoring everything. The files I'm interested in can be located most anywhere so I'm watching every filesystem. Most users aren't seeing this behavior so I'm trying to figure out why it's acting like this for the ones where it is happening. I don't think my bundle is set up to have any icons overridden.

Ok, quick check and it works. Many thanks to both of you!

Whoops, edited my post before seeing yours. Will look into that. Thanks!

Thanks for the response. Seems like a weird oversight. In any case, filed FB15370199. BTW, which method would you recommend in the meantime? I suspect the scraping but wanted to double-check.

Many thanks for the clarification/assurance. Admittedly, I am using it outside of its recommended use case so will file an FBA once the feature is out in production.

The next major release of my product is delayed because of this issue. And this definitely seems like a bug in the OS itself and not dependent on specific products. An OS feature has basically gone missing. Is pluginkit a valid workaround? I mean, it works, but I don't know if it's something that will be revoked without an official fix. Is there some assurance that Finder Sync Extensions are at least not being phased out and will continue to be supported? FBA #FB15300624 even if it's just a "me too" report.