How to Fix DNS Blocking Issues for DDownload on Desktop and Mobile

Some Internet providers implement DNS level blocking for specific domains. A recent example is DDownload, which in certain countries is currently inaccessible due to a forced DNS ban. When the DNS of the provider intercepts the lookup and redirects it to a false endpoint, the browser cannot validate the TLS certificate…and therefore returns a certificate error.

This post explains why the issue occurs and how to fix it on both desktop and mobile devices using safe technical methods.

Why the Error Happens

When a domain is blocked at DNS level, requests for its original IP are intercepted. The provider DNS returns a different IP that serves a block page or an invalid endpoint. Because the SSL certificate delivered by that endpoint does not match ddownload, the browser detects a mismatch…and reports a security error.

For example, Firefox shows:

“Warning Potential Security Risk Ahead”
“SEC_ERROR_BAD_CERT_DOMAIN”

This error does not indicate that DDownload has a compromised certificate. It only means the DNS reply has been altered by the provider.

How to Fix the Problem on Desktop

The most reliable solution is to stop using your provider DNS and switch to a neutral DNS resolver that does not perform domain level filtering.

Method 1. Change DNS at the System Level

Windows 10 and Windows 11

1. Open Settings

2. Go to Network and Internet

3. Select Adapter Options

4. Right click your active network and open Properties

5. Select Internet Protocol Version 4 (TCP IPv4)

6. Set manual DNS such as:

• 1.1.1.1 (Cloudflare)

• 8.8.8.8 (Google DNS)

• 9.9.9.9 (Quad9)

Confirm and restart the browser.

Linux (Ubuntu example)

1. Open Settings

2. Go to Network

3. Edit your active connection

4. Disable Automatic DNS

5. Insert DNS values above

Apply changes and restart NetworkManager if necessary.

Method 2. Change DNS Only in Firefox

If you want a browser only fix:

1. Open Firefox

2. Enter about:preferences

3. Go to Network Settings

4. Enable DNS over HTTPS (DoH)

5. Choose Cloudflare or NextDNS

Firefox will bypass the provider DNS and resolve DDownload correctly.

How to Fix the Problem on Mobile

Android

Android supports encrypted DNS since version 9.

1. Open Settings

2. Go to Network and Internet

3. Select Private DNS

4. Choose Private DNS provider hostname

5. Enter one of the following:

• dns.cloudflare.com

• dns.google

• dns.nextdns.io (requires an account)

This forces the device to ignore the provider DNS filter.

iPhone / iOS

iOS does not allow system wide encrypted DNS without a profile.

Use:

Option A. Install the Cloudflare 1.1.1.1 app
This app enables WARP or DoH…and bypasses DNS filtering.

Option B. Install the NextDNS configuration profile
Provides full encrypted DNS.

The certificate error shown by Firefox or other browsers is a direct result of DNS tampering by the provider. The domain itself is not faulty. Switching to a neutral or encrypted DNS resolver restores normal access to DDownload without security warnings.