P: Edit In External Editor does not work/function

Deborah, Please make sure you're using Lightroom 3.6, and not an earlier version. If you are, I suggest you delete the preferences file for Lightroom 3 and 4:
In this folder:
[user name]/Library/Preferences, delete the:
-- com.adobe.Lightroom3.plist file
-- com.adobe.Lightroom4.plist file.

I wrote a minute ago but not sure it went through. Question? What computer are you using, and what operating system. I'm using an iMac, Snow Leopard, PSE9 and Nik software. Thanks.

There are so many people who still don't have a fix, no matter what they've tried so I'm curious as to your situation.

Jeffrey this may or may not be a clue. i was soo frustrated - i decided to give up on LR 4.1 - just go back to a CLEAN LR 3 catalog - and, run LR 3 until the bugs are out. So, i started with LR 3 - a clean catalog - which i had saved - just in case
And, at import i copied some files (dng's) into my clean database - from 2 shoots .

I 'm now having the exact same problem with LR 3 that i am having with LR 4.1
with the edit in dialogue box.. what could account for that. i know this catalog - never touched LR 4 beta or LR 4 .

I have tried a PRAM reset (running an IMAC snow leopard). i'm out of ideas. help.
help.

I'm sure i'm running LR 4.1
And, nothing has changed for me between the 2 versions - I still do NOT get the EDIT in dialoge box when i try to modify a photo in CS5 from LR 4.1.
running an IMAC/ Snow Leopard - Help Help Help.!

Are you sure you're launching Lightroom 4.1 and not Lightroom 4.0?

I just reinstalled LR 4 and LR4.1RC and am still getting the error message about argument #1 and can not "edit in" my PSE9 or any of my NIK software. I am using Windows 7...help!!

All ok for me with PSE9

works for me with 4.1 and CS5

Loaded Lightroom 4.1 and everything is now working fine.

HELP! I downloaded the LR 4.1 RC. I'm running an IMAC, Snow Leopard, 4 GB of Ram.
While the RC did update a few of my curves adjustments (33) on a DB of 12,000 photos - that is not realiastic, since i make curves adjustments almost every time

Main issue is still - I can't get to CS5 (that i already had installed prior to LR 4) without going thru my Nik plug in's (Yeah for NIK!!). I don't get the dialogue box that let's me choose how to open my file in CS5. I do get that necessary dialogue box if i open any of the NIK plug ins.
yes, the nik plug ins are set up as presets.
yes, i have CS5 set up as a preset
yes, I have done a shut down
So, my only way to open a photo from LR to CS5 is to first open any Nik plug in - say ok - then it creates a TIFF file.. then i can go forward with my photo processing.
if this helps my Raw files are converted to DNG's.
help me.. i have deadlines - this takes to darn long.
help, drowning in photos in Texas, debi