The error message "Unexpected file extension type PNG found" suggests that the new environment has restrictions or misconfigurations related to file extensions. Since the same PNG file works in another environment, the issue is likely environment-specific.

Possible Causes & Solutions:

1. File Extension Restriction in OAC
   • Check if the new environment has security settings that restrict certain file types.
   • Go to Console → System Settings → Security and verify the allowed file types.
   • If PNG is restricted, add it to the allowed list.
2. Browser or Cache Issue
   • Try clearing your browser cache or using a different browser.
   • Test uploading the file in Incognito Mode.
3. Corrupt or Incomplete File Upload
   • Ensure the PNG file is properly formatted and not corrupted.
   • Try re-saving the PNG file using an image editor and re-uploading it.
4. OAC Version or Patch Differences
   • The environments might be running different OAC versions.
   • Check the OAC version in both environments (Console → About).
   • If the new environment is outdated, consider updating it.
5. Permissions Issue
   • Ensure the user role in the new environment has permission to upload images.
   • Test with an Admin user to see if the issue persists.
6. File Name or Encoding Issue
   • Check if the file name contains special characters or spaces.
   • Rename the file with a simple name (e.g., test.png) and try again.
7. Check OAC Logs for More Details
   • If you have access to the logs, check for any related error messages.

Next Steps:

• If the issue persists, check Oracle Support for known bugs or patches.
• If possible, compare configurations between the two environments.

Let me know if you need further help!