On the finder on Mac, the cover page appears as an icon with CBR files without any issues. But when I have a CBZ file, it just appears as generic white. What is interesting is if I utilize Mac finder search feature, I can see the cover page as the file icon, but only when utilizing search.
Anyone have this same issue? Or does the CBZ files work find in finder and perhaps I have another application installed causing a conflict. I also have Panels already associated with all file types of CBZ
The way iOS and MacOS works is that Apps asks the system to register as UTI handlers.
If two apps register to handle the same UTI, the most recent one installed wins.
So, most likely, another app on your Mac is capturing the file handler for CBZ
If you want to find out, there is a tool you can install to get uti information, called duti.
It can be installed with using Homewbrew and brew install duti
Then, find one of your CBZ files on your mac, and type mdls -name kMDItemContentTypeTree comic.bz
That will give you all of the UTI identifiers registered for that type of file on your mac.
You might get something similar to this
kMDItemContentTypeTree = (
"es.produkt.app.panels.file.cbz",
"public.data",
"public.item",
"public.content",
"public.archive",
"public.zip-archive",
"com.pkware.zip-archive"
)
Then you have to find which app is capturing it.
Panels exports its own UTI for cbz files es.produkt.app.panels.file.cbz
So you want to list all the apps registered for that UTI.
duti -i [UTI] shows all the apps registered for it.
In my case these are the apps registered for our own UTI (some apps register themselves to capture other apps UTI as well)
➜ duti -l es.produkt.app.panels.file.cbz
es.produkt.app.panels
net.kovidgoyal.calibre
cx.c3.theunarchiver
com.aone.keka
If you use duti -d [UTI] you will get the identifier of the app registered by default
➜ duti -d es.produkt.app.panels.file.cbz
es.produkt.app.panels
If, in your case you see a different app, that app is the one intercepting the app and the app extension to provide the thumbnail.
If you delete that app, or you delete Panels and re-install it, it should be the most recent UTI registrar and be the default app to open the file and provide the thumbnail.
I hope that helps
Thank you for the reply. That was exactly the cause. I had the program Comic Tagger installed on my machine to edit metadata of my comics and as soon as I removed that application it resolved issues with the UTI registrar. I no longer have any problems with the icons for CBZ files.
Amazing. I’ve never liked the UTI system, it’s quite flaky and depends on the order of the app were installed 
Hopefully one day Apple uses a better approach