At runtime, when you upload a file to an image or file attachment control and the file has no extension, no user-friendly error message shows.
- Ensure you have K2 Five (5.2) installed.
- Download the K2 Five (5.2) FP21 from K2 Partner and Customer Portal.
- Install the K2 Five (5.2) FP21 to apply the fix.
- Refresh the browser cache.