Backdrop: When operating in an Enterprise Portal environment and attempting to download a zip file from KM (Knowledge Management) using Internet Explorer the file appears corrupted and subsequently cannot be opened.
Testing the Behavior:
- Download a *.zip file from Knowledge Management to your local client machine using Internet Explorer
- Try to open the downloaded zip file on your local client machine
- You are unable to open it receiving the error that the file is invalid or corrupted or you get "Unexpected end of archive"
Why is this happening:
Zip files uploaded into Knowledge Management can have two different MIME types configured under System Administration -> System Configuration -> Knowledge Management -> Content Management -> Utilities -> MIME Types, either application/x-zip-compressed or application/zip
Compressing the files
- This mime type can be additionally compressed causing the file to appear corrupted when downloading
Resolution
- Check the MIME type of your zip file in the portal by clicking on the context menu of the file and going to Details -> Settings -> Properties
- Open the J2EE Visual Administrator tool
- Go to "Global Configuration -> Server -> Services -> HTTP Provider -> Properties -> Never Compressed"
- Make sure that the MIME type specified for this file in the portal is added to the NeverCompressed list of the HTTP Provider
- Also add the file extension to the NeverCompressed list of the HTTP Provider e.g. Add *.zip,application/x-zip-compressed
- After making the changes click on the "Update" button
7. Click on "Save Properties"
8. Restart the J2EE