Proworx File Naming: Legacy Filename Limitations and How to Recover

The Issue

Proworx NXT programs saved with long filenames may fail to open. The software was built around older file naming conventions, and exceeding the expected filename length can prevent the project from loading entirely — no error message, just a failure to open.

How to Find the Legacy Filename

If you cannot open a Proworx program, the fix is straightforward:

1. Open the .pwx or project file in Notepad (or any text editor).
2. Look for the original/legacy filename embedded in the file header. This is the filename the program was created with.
3. Rename the file (and any associated project files) back to the shorter legacy filename.
4. Use File > Save As to verify the name the program expects.

Why This Happens

Proworx NXT dates back to an era of 8.3 filename conventions (or close to it). When someone renames the project file to something more descriptive — adding site names, dates, revision numbers — the internal reference no longer matches the actual filename, and the software cannot resolve the path.

Prevention

• Keep Proworx filenames short. Use a naming convention like SITE_PLC1_R03.pwx rather than long descriptive names.
• Track revision details in a separate document or in the program comments — not in the filename.
• Before archiving, verify you can re-open the file after any rename.