Error when uploading WorldServer Return package or during "Save" after the upload - Central directory not found


When uploading a Return package, the translator gets the error message 

Central directory not found


Cannot find central directory

The same error happens if the Translate or Review step is completed without first fixing the error and uploading a correct Return package and the Task moves to the Save step.
Root Cause:
The error is caused by a damaged SDLXLIFF file included in the Return package uploaded by the translator or reviewer. The translator has seen the error during upload, but he/she has ignored it. The same error appears in SDL Trados Studio when the SDLXLIFF is saved as target. Specifically, the error relates to the embedded dependency file and is possibly due to having embedded the wrong file when prompted in SDL Trados Studio.
This issue comes from a damaged Return package. The translators or reviewers working with WorldServer Studio packages should always do a Save target as... in SDL Trados Studio before creating and uploading a Return package to WorldServer. If SDL Trados Studio reports an error, this error should be fixed and not ignored. If ignored, the same error will be transferred to WorldServer during the upload and will display at the next Save or Save target Step.

Resolution 1:

Resolution 2:

If no originally exported WSXZ package is available for re-translation, follow these steps (these are steps for SDL Support since they might be too technical for the end-user):
  1. Download the source file corresponding to the affected task
  2. Unpack the Return package (rename it to *.zip and unzip it)
  3. Open affected bilingual file in SDL Trados Studio
  4. Go to the temp folder of your user on your local machine (enter %temp% in the Windows Explorer address bar)
  5. Delete or move all files in the temp folder
  6. Save the SDLXLIFF bilingual file in SDL Trados Studio and close it.
  7. Re-open the SDLXLIFF bilingual file: You will be prompted a warning that the dependency file is missing with the option to embed it
  8. Click ‘Yes’ and select the source file from Step #1 (make sure to select all formats in the open file window, so you can see all files and select the source file)
  9. Save the bilingual file in SDL Trados Studio (File > Save)
  10. Replace the original sdlxliff file in the return kit with the one from # 9
  11. Zip the fixed SDLXLIFF file and rename the ZIP file to *.wsxz
  12. Upload the Return package and observe that no more error appears during upload.