Here are the 5 steps to fix “File Cannot Be Downloaded Securely”
Step 1: Navigate to Settings
Step 2: Search “Content”
Step 3: Scroll down to “Insecure Content”
Step 4: Click Add under Allow
Step 5: Add a direct URL to the download file or use a wild card in the form like the example in the image below [*.]example.com.
You should now be able to download your file without having to restart your browser.