Script won't quit; AppleEvent timeouts and Errors! Any advice?

Question

Hi Forum,
Applescript is driving me crazy... I'm using quite a bunch of scripts on a highly automated server which are supposed to shuffle files and folders, process images, create and export XML files, etc.
All scripts are tested multiple times and run without a problem, however, when I put them in a Cron to execute during nighttime, I get mysterious messages in the morning like:
"AppleEvent timed out" or
"NSReceiverEvaluationScriptError:4"
Of course, all folloving scripts and events are then stucked and even the weekly reboot will not be executed! And I can't understand why; when I launch the apps (the scripts are saved as executable applications) manually, they never fail!
Anyone any idea? How could I trap this problem? Many thanks in advance!
Kind regards,
AS

Answer 1

In fact, the same scripts do not always run into problems; one day it works, the next not. So enabling logging would be helpful in any case... but how can I do this?
Concerning the user, I already tried running the script with the only user account as well as root; the problems are basically the same. The system goes never to sleep and only a screensaver is activated. Also the scripts do not rely on any dynamic path, only fixed AS pathes are used, however they mostly point to server volumes!
I can post a (simplified) script as an example. This script is in real too big to post here but this should give you an idea. It basically looks for TIFFs in an INPUT folder and generates downsampled JPEGs in an OUTPUT folder if they do not exist yet. All this is logged in a file and finally a message with the results is being mailed:
tell application "Finder"
set the_date to (current date) as string
if exists disk "SERVER_VOLUME" then
set theInputFolder to folder "INPUT" of disk "SERVER_VOLUME"
set theInFiles to every file of theInputFolder
set theOutputFolder to folder "OUTPUT" of disk "SERVER_VOLUME"
set theOutFiles to every file of theOutputFolder
set theLoggingPath to a reference to "SERVER_VOLUME:" as string
set log_path to theLoggingPath & "tiff.log"
set logfilecontent to (open for access file log_path with write permission)
try
write the_date & return to logfilecontent starting at eof
on error
close access logfilecontent
end try
close access logfilecontent
repeat with x from 1 to length of theInFiles
set theInFile to file ((item x of theInFiles) as string)
set extension hidden of theInFile to false
update theInFile
end repeat
repeat with y from 1 to length of theOutFiles
set theOutFile to file ((item y of theOutFiles) as string)
set extension hidden of theOutFile to false
set label index of theOutFile to 4
update theOutFile
end repeat
set theExisting to every file of theOutputFolder whose name extension = "jpg"
count (every file of theOutputFolder whose name extension = "jpg")
set ExistingCount to result
repeat with z from 1 to length of theExisting
set theImage to file ((item z of theExisting) as string)
set the file_name to the name of theImage
set logfilecontent to (open for access file log_path with write permission)
try
write "[EXST] " & file_name & return to logfilecontent starting at eof
on error
close access logfilecontent
end try
close access logfilecontent
end repeat
set theTiffs to every file of theInputFolder whose name extension = "tif"
count (every file of theInputFolder whose name extension = "tif")
set TiffCount to result
tell application "Image Events"
launch
repeat with a from 1 to length of theTiffs
-- the image processing is done and logged
end repeat
quit
end tell
tell application "Mail"
launch
-- a mail is sent
quit
end tell
else
-- a restart procedure is initiated
end if
end tell
In the morning I mostly have the JPEGs, the Log and the Mail, yet the script failed to quit with an error message and all further scripts are blocked!
Thanks again!