First update to latest version of UltraEdit.

Second I found the problem. The installers of UltraEdit v13 do not set anymore one registry key required for UltraCompare Professional to launch uedit32.exe when it is not already running. I will report this to IDM support.

In the mean time fix that missing registry key manually.

Open in UltraEdit a new, blank ASCII text file and paste following text:

REGEDIT4

[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\App Paths\uedit32.exe]
@="C:\\Program Files\\IDM Computer Solutions\\UltraEdit-32\\uedit32.exe"
"Path"="C:\\Program Files\\IDM Computer Solutions\\UltraEdit-32"

Adapt the path to uedit32.exe to your installation if necessary. Note: You must write 2 backslashes instead of only 1 as shown above for every directory.

Save the text file with extension reg, for example UE_App_Path.reg.

Double click on this registry file to import it's content into your registry. You must have administrator privileges to import this file.

Then UltraCompare Professional can find uedit32.exe and run it.

This registry key with it's 2 string values could be missing for all users who installed UltraEdit-32 v13 without having installed a previous version before.

Can you be more specific? Which version of UltraEdit do you use and which version of UltraCompare Professional?

Have I understand your right? Do you compare two Java packages (ZIP archives) and try to open one of the files in the archives with UltraEdit?

I think, UltraCompare Professional is not designed to do that. That would require unpacking the file to a temp folder, then start UltraEdit with the file in the temp folder and when UltraEdit modifies the file, UltraCompare Professional must detect that change and repack the updated file into the archive. Contact IDM support by email if you want clarification if UC supports it or not. Well, if UC does not support it, then the "Open in UltraEdit" toolbar and menu items should be disabled when comparing files in archives.

I have tried it yet with 2 files:

C:\a\b\c\d\e\f\g\h\i\j\k\ejb\session\stateless\test.txt
F:\Temp\Test.txt

When I double click into one of the 2 files displayed in UC, UltraEdit v14.00b is started and it opens both files.

Have you really tested it with that directory names or is your full file name MUCH, MUCH longer, maybe longer than 259 characters which is the maximum length of an ANSI file name as defined by Microsoft. (MAX_PATH is 260 but includes the terminating NULL character of ANSI strings.) Also short names (FAT16) supports only up to 8 levels - root directory (which is for Windows file systems not a directory - crazy!), 6 subdirectories and the file name. It looks like the short name is passed from UC to UE in your case. This happens normally by Windows automatically if either the full file name is longer than 259 characters or the full file name contains 1 or more Unicode characters which cannot be correct handled in ANSI strings.