SecuExtender IPSec VPN Client – Activation Errors and Troubleshooting

When activating the Zyxel SecuExtender IPSec VPN Client, different error codes can appear.

The problem can be related to:

• the license key;
• the activation or licensing server;
• the Internet connection;
• firewall or proxy settings;
• Windows administrator rights;
• an incorrect activation code;
• a previous installation of SecuExtender;
• the license type or license status.

This article explains the most common activation errors and the recommended troubleshooting steps.

Important: Error 70 does not always mean that there is a problem with administrator rights. Zyxel also reports cases where Error 70 is caused by problems connecting to the licensing server or by the license still being linked to a previous installation.

Quick Troubleshooting Table

Recommended Support Workflow

When a SecuExtender activation error is reported, use the following order.

Step 1 – Identify the Client

Check:

• Windows or macOS;
• SecuExtender version;
• IPSec or SSL VPN;
• Perpetual or Subscription license.

Step 2 – Get the Exact Error

Record the exact:

Error Code / Error Message

Step 3 – Check the License

Check:

• Is the license key correct?
• What type of license is it?
• Was it activated before?
• Was the computer or Windows recently replaced?
• Is it a legacy Perpetual/EOL license?

Step 4 – Check Administrator Rights

For Error 000 and Error 070:

Run as administrator → try activation again.

Step 5 – Check Network Connectivity

Check the Internet connection and run:

nslookup tgbosa.com

Make sure the network does not block:

tgbosa.com
*.tgbosa.com

over HTTPS.

Step 6 – Check Firewall and Proxy

This is especially important for:

• Error 050;
• Error 053;
• Error 070.

Step 7 – Decide if Zyxel Support Is Required

Contact Zyxel Support when:

• the license needs backend verification;
• a supported license is still linked to an old computer;
• the license and activation code do not match;
• the licensing server is reachable but activation still fails.

For legacy Perpetual/EOL licenses, remember that license reset or reactivation may no longer be available.

Key Point for Support

Do not treat Error 070 as only an administrator-rights problem.

For Error 070, always check these three areas:

1. Windows permissions
   → Run as Administrator
2. Licensing infrastructure
   → tgbosa.com, DNS, HTTPS, firewall and proxy
3. License status
   → Previous computer, Windows reinstall, previous activation or EOL license

This approach helps identify the real cause faster and avoids unnecessary reinstallations or troubleshooting steps.

Error 070 – Internal Error

Error 070 is one of the most important activation errors because it can have several different causes.

Possible Cause A – Administrator Rights

Zyxel documentation lists missing administrator rights as one possible reason for Error 070.

What to do

1. Close SecuExtender.
2. Right-click the application.
3. Select Run as administrator.
4. Try the activation again.

Possible Cause B – Licensing Server Connection

Error 070 can also happen when SecuExtender cannot get the required license information from the Zyxel licensing server.

Zyxel refers to:

tgbosa.com

What to check

Open Command Prompt and run:

nslookup tgbosa.com

The domain should resolve correctly.

Also check that the firewall, proxy or other security device does not block HTTPS access to:

tgbosa.com
*.tgbosa.com

Possible Cause C – Firewall or Security Software

A computer can have a working Internet connection but still be unable to contact the licensing server.

This can happen when:

• Windows Firewall blocks the connection;
• company firewall blocks the connection;
• proxy blocks the connection;
• antivirus/security software blocks the connection;
• network security rules block the licensing traffic.

This is especially important if activation works on another network or another computer.

Possible Cause D – License Still Linked to Previous Installation

Error 070 can also occur after:

• reinstalling Windows;
• replacing the computer;
• reinstalling SecuExtender;
• moving the license to another installation.

In this situation, the license may still be linked to the previous installation.

The license status may need to be checked or reset by Zyxel Support.

1. Error 000 – Internal Error

Cause

SecuExtender cannot complete the activation process.

According to Zyxel, one possible reason is that SecuExtender was started without administrator rights.

What to check

1. Close SecuExtender.
2. Right-click SecuExtender.
3. Select Run as administrator.
4. Try to activate the license again.

If the error is still present, continue with the network and licensing server checks.

2. Error 031 – License Not Found

Cause

The entered license number or license key is incorrect or cannot be found.

What to check

• Check the license key.
• Make sure there are no typing errors.
• Make sure the license is for SecuExtender IPSec VPN Client.
• Check that the correct product license is being used.

If the license key is correct but the error continues, the license status should be checked with Zyxel Support.

3. Error 033 – License Already Activated

Cause

The license has already been activated.

This can happen when:

• moving SecuExtender to another computer;
• reinstalling Windows;
• replacing a computer;
• reinstalling SecuExtender.

A license can remain linked to the previous computer or installation.

What to check

For supported licenses:

1. Check if the license was already activated on another computer.
2. Check if Windows was recently reinstalled.
3. Check if the computer was replaced.
4. If the license is still linked to the old installation, contact Zyxel Support.

Zyxel may need to check or reset the license on the backend.

Important: For old Perpetual licenses, license reset or reactivation is no longer supported. See the Legacy / EOL Licenses section below.

4. Error 034 – Wrong Software / License Type

Cause

The license is for a different Zyxel product or software.

What to check

Check:

• the license type;
• the product name;
• IPSec vs. SSL VPN;
• Perpetual vs. Subscription license.

Make sure the license is intended for SecuExtender IPSec VPN Client.

5. Error 050 – Activation Failed

Cause

SecuExtender received an incorrect or invalid activation code.

Possible reasons include:

• proxy settings;
• firewall;
• security software;
• the activation code was changed or blocked during communication.

What to check

1. Check the proxy settings.
2. Check the firewall.
3. Check antivirus or other security software.
4. Try the activation again.
5. If available, try Manual Activation.

If the activation works after temporarily disabling the firewall, create the correct firewall rule instead of leaving the firewall disabled.

6. Error 051 – License / Activation Code Mismatch

Cause

The license number and activation code do not match.

What to check

• Check the license number.
• Make sure the correct license is being used.
• If the information is correct and the error continues, contact Zyxel Support.

Zyxel may need to check the license information.

7. Error 052 – Activation Code Not Recognized

Cause

SecuExtender cannot recognize the activation code.

What to check

1. Try the activation again.
2. Check the license information.
3. If the problem continues, contact Zyxel Support.

8. Error 053 – Cannot Connect to Activation Server

Cause

SecuExtender cannot connect to the Zyxel activation server.

Possible reasons:

• no Internet connection;
• activation server is temporarily unavailable;
• firewall blocks the connection;
• proxy blocks the connection;
• security software blocks the connection.

What to check

1. Check the Internet connection.
2. Try the activation again later.
3. Check the firewall.
4. Check the proxy settings.
5. Try Manual Activation, if available.

9. Error 055 – Activation Code Error

Cause

SecuExtender cannot correctly process the activation code.

The activation code may be invalid or corrupted.

What to check

1. Start the activation process again.
2. Get a new activation code.
3. Try the activation again.

If the problem continues, contact Zyxel Support.

10. Legacy / EOL Perpetual Licenses

This is an important point when troubleshooting old SecuExtender installations.

Zyxel has ended support for the old SecuExtender IPSec Perpetual / Lifetime licenses.

Zyxel announced:

• registration for Perpetual licenses ended on 31 March 2023;
• the old SecuExtender IPSec Windows Client reached EOL in October 2023;
• activation and reactivation of old Perpetual licenses are no longer supported.

What does this mean for Support?

If a customer says:

“My old SecuExtender license worked before, but after reinstalling Windows I now get Error 33 or Error 70.”

Do not immediately recommend reinstalling the software or resetting the license.

First check the license type.

If it is a legacy Perpetual license, Zyxel may no longer be able to reset or reactivate it.

In this case, the customer should be informed that the license is an old EOL product and a supported solution should be considered.

11. Security Consideration for Legacy Clients

There is also a security reason to avoid continuing to use old Perpetual SecuExtender versions.

Zyxel has reported a security vulnerability in the legacy SecuExtender IPSec Perpetual version 3.8.204.61.32.

Because the product is already EOL, Zyxel no longer provides normal development and security updates for this old client.

For this reason, when troubleshooting an old Perpetual installation, consider moving the customer to a supported solution instead of trying to restore the old installation.