Issue with Opening Diagram Files in diagrams.net Using URLs

[KSVprod]

Problem Description:
We are facing an issue when trying to open diagram files in diagrams.net using URLs. Our diagrams.net server is deployed using a Docker container. When attempting to open a diagram file via a URL like http://localhost:8081/uploads/Diagram1.drawio, we encounter a problem where the file doesn't open in diagrams.net. Instead of displaying the diagram's content, we see a blank screen.

Steps to Reproduce:

1. Start a Docker container with diagrams.net on the server.
2. Ensure that the container is successfully running and accessible at http://localhost:8081.
3. Upload a diagram file with the .drawio extension to the server using the upload form.
4. Visit a URL like http://localhost:8081/uploads/Diagram1.drawio.
5. In diagrams.net, observe a blank screen instead of the loaded diagram.

Expected Behavior:
We expect that using a URL to open a diagram file in diagrams.net will result in the file being correctly loaded and displayed on the screen.

Additional Information:
We have verified that the diagram file is indeed uploaded to the server and resides in the uploads folder. Additionally, we've ensured that the web page containing the URL to open the file is correctly linked to diagrams.net.

Environment:

Operating System: Mac OS 13.4.1
Browser Version: Safari 16.5.2 (18615.2.9.11.10)
Docker Version: 4.22.0 (117440)

Additional Notes:
We also noticed the message "Error loading file. Service unavailable or blocked" within diagrams.net when attempting to open the diagram file.