The application Finder.app can't be opened.

Sad to see that Apple hasn't resolved this issue.

Peter's trick (/System/Library/CoreServices/Finder.app/Contents/MacOS/./Finder) works for me - for now.

If it helps; I run into this situation when deleting a large file or folder from a Samba share.

This just happened to me after applying the 10.6.5 update. Upon rebooting, Finder would not restart, giving the -10810 message. I tried restarting from the apple menu, but this wouldn't work; it told me to quit Safari even though I already had. Using the terminal, I checked that Safari was not running and seeing nothing else unusual, I used 'sudo reboot' and everything came back normally.

I am having the same 10810 The application finder cannot be opened. What do I do?

Wow. I got this Finder error 10810 recently on my two-month-old iMac (i5 27" Mac OS X 10.6.4).

The first time I saw it was after I had inserted a card from my camera into the slot on the side. After the forced restart, Disk Utility said that my internal hard drive required repair, (invalid catalogue count or something), and so I had to start from the install CD and fix that. The camera's card was able to be read fine subsequently, at least once.

Then when an external hard disk was plugged in (via USB, not Firewire), same error. The external disk was some Windows format, probably FAT32.

So I searched the web (which knows all answers 😉 ) and to my surprise, this is a long-known bug with a very long thread at Apple Discussions. But no actual fixes, apparently. How disappointing!

I haven't applied the 10.6.5 update yet; I'll make sure that I do a disk utility check beforehand. Perhaps that'll help. (Anyone care to bet? Hehe.)

Just a few months old!

Aurel: You seem to be hitting the same cause of this error as me - external disk formatted as FAT32. I've never seen the issue when using anything formatted otherwise (though I understand others here have).

I'm running 10.6.5 and have not seen this error crop up, but that definitely does not mean its gone. Sorry I cannot give you better assurance.

Sorry: my disks are all hfs+…

NO problem with 10.6.5 so far, but I'm not holding my breath…

I have external FAT32 disks, even NTFS disks, but the problem only occurs with SMB shares ...

I do not know why but I somehow was able to update to 10.6.5 and when I came back to it all was working fine. Let's hope it continues.

Interesting... I had personally never seen this issue on either of my systems up through 10.6.4. Now, after updating my server to 10.6.5 (via full combo updater) I've seen it twice on my MBP. Both times were the same as what Jack_Overfull described--had an AFP volume mounted over the network, it flaked out abruptly for no apparent reason, hanging the Finder and anything else that attempted to access it. Killing Finder and attempting to reopen resulted in the 10810 error, nor was I able to soft restart--a standard reboot command didn't do anything, and "sudo reboot now" just hung at the blue screen with spinner after the user session logged out.

This happened once with the MBP on 10.6.4, and once with it on 10.6.5, which is two times more than I've seen it to date.

There are two odd things, which won't really help anybody, but I find interesting:

1) This is unquestionably the first time I've ever seen this particular error, and I installed 10.6.0 on the day it shipped, and every OS update in between. No difference in the network mount behavior, either--the server volume is always mounted. I had seen similar behavior--a flaked-out AFP mount hanging the entire I/O subsystem of the OS--before, but it's actually been much LESS common under 10.6 than before--I hadn't seen a single such a hang on my laptop since I installed 10.6 (I have seen them periodically on my i7 iMac, though they were not accompanied by this error and may have been due to a non-network mount).

Phrased differently, the "Unable to reconnect to network volume" floating dialogue has worked near-flawlessly in 10.6 to date.

2) At the exact same time as this error occurred, my iMac also hung with the same behavior. With one exception: Finder did NOT give this error, it just hung when you tried to relaunch it. "sudo umount -f /Volumes/share" hung, and stuck processes refused to be killed regardless of flags, which is the behavior I usually see on hung I/O.

Also weird, the server was absolutely fine--it reported no problems, the drive was running smoothly, I could unmount and mount it manually via Disk Utility with no problem, and I could turn file sharing off and on without any complaints.

Could obviously just be a nasty coincidence, but it does seem strange that I only started seeing this error after installing 10.6.5 on my server.

I'm not sure if it's related, it could be coincidence, but could it be related to applications like Parallels Desktop (I'm running v5), or Paragon NTFS for MacOS X ...?

One can hardly do a thing when this happens. A lot of activity is initiated via Finder and revolves around it, it's a central component of the MacOS. When it occurs, the only hope is a forced restart of the entire system.

That Apple has not seen fit even to contribute to this thread of some 550 posts - less still provide a fix on a very significant and easily reproducible flaw - is rather surprising, not to say alarming.

I have neither Parallels or Paragon so...

I tried to restart with Safari open so that I had access to "restart". It would not work because Safari would not quit. I am not sure how it finally corrected itself. I did something and tried again to update to 10.6.5 and left the house., came home later and it was updated and working fine.

I also wonder where Apple is in all of this. They seem to be lost. Apple, how about responding not to mention fixing this.

Just thought I'd mention what caused it for me and what solved it. I had a webdisk window open and finder was trying to preview a really huge video file. It gave me the beach ball of death so I force quit finder but then it wouldn't open back up. I finally fixed it by turning off my network card interface and turning it back on. Hope this helps someone.

I'll have to try disabling my network next time this happens. Thanks.