Mac OS 10.9 slow finder and open / save dialog box workaround

After upgrading to Mac OS 10.9, Mavericks, our computers have been running slowly when using Finder or using

File open dialog
File open dialog

the File – Save/Open dialog box in any application. It took up to 30 seconds to get files to show. It was a real time waster. In our business, time is everything.

Our first workaround was to close then re-open the application. Though it worked, that was pretty wasteful and miserable. So we tried trashing the Finder preferences file:

com.apple.finder.plist

Preferences library
Preferences library

It can be found in Library – Preferences. You can get there by opening Finder, selecting the menu option Go, then holding the OPT key, then selecting the Library option. Navigating down to Preferences, you can find the com.apple.finder.plist file. Just delete it. Doing so will reset the Finder preferences and, hopefully, fix the Finder slowness for you.

That didn’t work for us. A general solution to any Mac problem is to trash the preferences file. It’s inconvenient but it usually works. Just not in this case.

Instead, we learned that the workaround was to modify one of the system files. If you aren’t sure what you are doing, take your computer to a professional. We aren’t responsible if something goes wrong(!).

Here are the steps we followed to fix the issue:

Nano interface
Nano interface
  • Open a Terminal window
  • Type  sudo nano /etc/auto_master
  • Enter the administrator password
  • Find the line that says this: /net -hosts -nobrowse,hidefromfinder,nosuid
  • Use the arrow keys and add a pound sign (#) before the / character
  • Now you have  #/net -hosts -nobrowse,hidefromfinder,nosuid
  • Click Control+O to save the file
  • Click Control+X to exit the Nano editor
  • Type in sudo automount -vc
  • This will flush the cache

Now, go to a File Open/Save dialog and see what happens. It fixed the lag for us completely.

It’s important to note that you have made this modification, so when the next Mavericks updates come out (10.9.2 or higher) and there is a fix for this problem, you will have to remove this workaround. Otherwise, something might not work. We’re not sure what might break, but we’ll deal with that and post it here when the time comes.