How to Prevent URL Loading Errors at the Firewall Level

When course content like videos or PDFs won’t load in ProProfs Training Maker, the issue is often caused by your organization’s firewall blocking required URLs. This article explains how firewalls interfere with content loading, which domains need to be allowed, and what steps to take if issues continue.

What Does a Firewall Have to Do With Course Loading?

Your firewall controls what content can pass through your network. If it blocks a domain used by ProProfs to deliver video, audio, or document files, those resources will fail to load, even if the rest of the platform appears functional.

ProProfs uses secure third-party services like Amazon S3 to store videos and Cloudflare to speed up content delivery. If these services are not whitelisted, your learners may see:

• Videos are stuck on an infinite loading screen

• Error messages like "file not found" or "failed to load resource"

• Blank areas where course files should appear

These errors prevent learners from completing training and create support overhead for admins.

A video URL giving an error may look like this:

How to Identify a Firewall-Related Issue

You're likely facing a firewall issue if:

• Videos and files fail to load across multiple users within the same office network

• The same course works fine on a different network (e.g., mobile hotspot or home Wi-Fi)

• The browser console (F12 to Network tab) shows blocked requests from Amazon S3 or Cloudflare URLs

These signs point to your firewall blocking the URLs responsible for delivering course media.

What to Whitelist (and Why It Matters)

To allow ProProfs content to load correctly, your firewall must permit traffic to these domains:

• *.proprofs.com - core training platform

• *.proprofstraining.com - used for content and course delivery

• *.amazonaws.com - hosts videos, PDFs, and attachments

• *.cloudflare.com - secures and speeds up global content delivery

Using a wildcard (*.) before the domain allows all necessary subdomains. Without this, individual media URLs may still get blocked, even if the main site loads.

How to Communicate With Your IT Team

If you're not managing your firewall directly, share this with your IT or network admin:

We're using ProProfs Training Maker for internal training, but videos and files aren't loading. Can you whitelist the following domains across our firewall and proxy settings?
*.proprofs.com, *.proprofstraining.com, *.amazonaws.com, *.cloudflare.com.
These services are used to securely deliver course content.

This request gives IT all the technical context they need to resolve the issue without back-and-forth.

If the Problem Persists After Whitelisting

Sometimes local browser or system settings interfere with content loading even after firewall changes. Here’s what to try next:

• Clear browser cache and restart the browser

• Try a different browser to check if it's browser-specific

• Test on a different network to isolate the issue from the local infrastructure

• Contact ProProfs Support with the course URL, error screenshot, and browser/OS details

Providing exact details helps Support troubleshoot faster and avoid generic solutions.