Couldnt communicate with a helper application when connecting iPhone

I know this seems to have been solved, but I ran into the issue myself this morning and wanted to explain how I fixed it. My main iTunes library is on an external drive, but I don't have it with me right now. I first ran into the issue when I connected the phone through Finder. Once I opened up Music and AppleTV and created new libraries on the local SSD, it corrected itself. I think someone else has it right: While Finder should theoretically work by itself, it seems to be connected still to Music and Movies/TV.

Hope this is useful!

Thanks. Opening the Music app and connecting that way worked. Finder connection started working after that.

I was having the same issue. I have my iTunes folder on a NAS. When I reconnected to the NAS, the issue went away. I'm guessing that there's something in that folder that Finder needed to find. I hope this helps someone.

I couldn’t get it to work with finder in Catalina. But if you open Apple Music it connects via that. Also I’m a developer and Xcode connects and I’m able to install my applications so this appears to be an issue with the finder app.

I also have this problem not only with my iPhone XS but also with my iPad Pro on my iMac Pro. All software is latest and I have tried the same things mentioned in first post to try and fix it. I also found that I can communicate with the iPad and iPhone after logging into another user account on same computer or my laptop which has been upgraded to Catalina. This indicates that the issue of not being able to communicate to the helper application is specific to my main user account on my iMac and also not an issue with the iPhone or iPad. .

I will continue to work on this to find a solution but can’t fully commit to Catalina until this is resolved. Any suggestions will be appreciated.

You’re welcome! Yes paired with the previous comment of the NAS this does appear to be some lingering legacy issue of iTunes formerly handling this duty and finder still needing something from “iTunes” Before it can proceed. Based on the NAS issue it appears that finder always expects the music libraries to be present.