# License key issue

**URL:** <https://forum.radzen.com/t/license-key-issue/21760>\
**Category:** Radzen Blazor Studio\
**Created:** [November 3, 2026, 7:18am UTC](https://forum.radzen.com/t/license-key-issue/21760 "2026-11-03T07:18:55Z")\
**Posts on this page:** 12\
**Page:** 1

<div class="post-metadata">

**Author:** ![Kield](https://forum.radzen.com/letter_avatar_proxy/v4/letter/k/dec6dc/32.png) [@Kield](https://forum.radzen.com/u/Kield)\
**Post date:** [November 3, 2026, 7:18am UTC](https://forum.radzen.com/t/license-key-issue/21760/1 "2026-11-03T07:18:55Z")

</div>

I get this error when I try to open Blazor Studio

 ![2026-11-03 08_02_53-Radzen Blazor Studio](https://forum.radzen.com/uploads/default/original/3X/6/6/66f1914759c9e51d9cad1847b3700b961146e154.png)

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<div class="post-metadata">

**Author:** ![enchev](https://forum.radzen.com/user_avatar/forum.radzen.com/enchev/32/16_2.png) [@enchev](https://forum.radzen.com/u/enchev)\
**Post date:** [November 3, 2026, 7:21am UTC](https://forum.radzen.com/t/license-key-issue/21760/2 "2026-11-03T07:21:57Z")

</div>

Make sure you have access to internet and [radzen.com](http://radzen.com).

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<div class="post-metadata">

**Author:** ![Kield](https://forum.radzen.com/letter_avatar_proxy/v4/letter/k/dec6dc/32.png) [@Kield](https://forum.radzen.com/u/Kield)\
**Post date:** [November 3, 2026, 7:27am UTC](https://forum.radzen.com/t/license-key-issue/21760/3 "2026-11-03T07:27:49Z")

</div>

It should be okay, unless it is a firewall thing. No problem reaching [radzen.com](http://radzen.com)

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<div class="post-metadata">

**Author:** ![enchev](https://forum.radzen.com/user_avatar/forum.radzen.com/enchev/32/16_2.png) [@enchev](https://forum.radzen.com/u/enchev)\
**Post date:** [November 3, 2026, 7:31am UTC](https://forum.radzen.com/t/license-key-issue/21760/4 "2026-11-03T07:31:11Z")

</div>

Thanks for the screenshot. The important part is the error text:

```auto
SyntaxError: Unexpected token '<', "<!--samlch"... is not valid JSON

```

Blazor Studio sends the license key to our server and expects a JSON reply. What it received instead is an HTML page starting with `<!--samlch…`, which is the beginning of a SAML sign-in challenge page. Such pages are produced by corporate secure web gateways and SSL-inspecting proxies that authenticate users through single sign-on (Zscaler, Netskope, Cisco Umbrella, GlobalProtect, Forcepoint and similar). In other words, the request never reached [radzen.com](http://radzen.com). Your proxy intercepted it and answered with its own login page.

This also explains why [radzen.com](http://radzen.com) opens fine in your browser. The browser has already signed in to the proxy and carries its session cookie. Blazor Studio makes its own HTTP request without that cookie, so the proxy treats it as an unauthenticated client and returns the SAML page.

You can confirm this from a terminal, which behaves like Blazor Studio rather than like the browser:

```powershell
Invoke-WebRequest https://www.radzen.com -UseBasicParsing | Select-Object -ExpandProperty Content | Select-Object -First 3

```

If the output starts with `<!--samlch` instead of the Radzen homepage, the proxy is intercepting non-browser traffic.

To resolve it, ask your IT department to whitelist [radzen.com](http://radzen.com) for Blazor Studio, or to exempt it from SAML authentication and SSL inspection. As a quick check you can also validate the key once from a network without the corporate proxy or with the VPN client disconnected.

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<div class="post-metadata">

**Author:** ![Kield](https://forum.radzen.com/letter_avatar_proxy/v4/letter/k/dec6dc/32.png) [@Kield](https://forum.radzen.com/u/Kield)\
**Post date:** [November 3, 2026, 7:52am UTC](https://forum.radzen.com/t/license-key-issue/21760/5 "2026-11-03T07:52:13Z")

</div>

> [@enchev](#):
>
> `Invoke-WebRequest https://www.radzen.com -UseBasicParsing | Select-Object -ExpandProperty Content | Select-Object -First 3`

I changed it to -First 15 as it showed the whole page. Result:

 Blazor Components, Visual Designer & AI Agent Support | Radzen {

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<div class="post-metadata">

**Author:** ![Kield](https://forum.radzen.com/letter_avatar_proxy/v4/letter/k/dec6dc/32.png) [@Kield](https://forum.radzen.com/u/Kield)\
**Post date:** [November 3, 2026, 7:55am UTC](https://forum.radzen.com/t/license-key-issue/21760/6 "2026-11-03T07:55:54Z")

</div>

Or as print:

 ![image](https://forum.radzen.com/uploads/default/original/3X/f/7/f73913152e55a61c9aa6e1752f21a6cb892ec369.png)

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<div class="post-metadata">

**Author:** ![enchev](https://forum.radzen.com/user_avatar/forum.radzen.com/enchev/32/16_2.png) [@enchev](https://forum.radzen.com/u/enchev)\
**Post date:** [November 3, 2026, 8:00am UTC](https://forum.radzen.com/t/license-key-issue/21760/7 "2026-11-03T08:00:42Z")

</div>

Can you try:

```auto
curl.exe -s -X POST -H "Content-Type: application/x-www-form-urlencoded" --data "product_permalink=test&license_key=test" https://app.radzen.com/v2/licenses/verify

```

If you get HTML starting with `<!--samlch` instead, your proxy is intercepting requests to `app.radzen.com` and that is what Blazor Studio runs into. Ask your IT department to allow `app.radzen.com` (or exempt it from SAML authentication and SSL inspection).

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<div class="post-metadata">

**Author:** ![Kield](https://forum.radzen.com/letter_avatar_proxy/v4/letter/k/dec6dc/32.png) [@Kield](https://forum.radzen.com/u/Kield)\
**Post date:** [November 3, 2026, 8:09am UTC](https://forum.radzen.com/t/license-key-issue/21760/8 "2026-11-03T08:09:05Z")

</div>

I get json in return  
{"success":false,"message":"License key not found"}

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<div class="post-metadata">

**Author:** ![enchev](https://forum.radzen.com/user_avatar/forum.radzen.com/enchev/32/16_2.png) [@enchev](https://forum.radzen.com/u/enchev)\
**Post date:** [November 3, 2026, 8:13am UTC](https://forum.radzen.com/t/license-key-issue/21760/9 "2026-11-03T08:13:15Z")

</div>

Good, so a plain request to `app.radzen.com` goes through. That leaves two differences between `curl.exe` and Blazor Studio, and the SAML page must come from one of them:

1. **System proxy.** Blazor Studio is an Electron app and uses the Windows proxy settings, including a PAC script if one is configured. `curl.exe` ignores them and goes straight out. If your network has a proxy, Blazor Studio's request is going through it and `curl` was not.
2. **Browser user agent.** SAML gateways only challenge clients that look like a browser, since only a browser can complete the sign-in. Electron identifies as Chrome; `curl` does not.

Two checks, both in PowerShell:

```powershell
[System.Net.WebRequest]::GetSystemWebProxy().GetProxy("https://app.radzen.com/").AbsoluteUri

```

If this prints `https://app.radzen.com/` there is no proxy configured for that host. If it prints a different address, that is the proxy Blazor Studio goes through, and this request should reproduce the problem because it uses the same proxy settings:

```powershell
try { (Invoke-WebRequest https://app.radzen.com/v2/licenses/verify -Method Post -ContentType "application/x-www-form-urlencoded" -Body "product_permalink=test&license_key=test" -UseBasicParsing).Content } catch { $r = $_.Exception.Response; if ($r) { (New-Object IO.StreamReader($r.GetResponseStream())).ReadToEnd() } else { $_.Exception.Message } }

```

And the same request with a Chrome user agent:

```auto
curl.exe -s -A "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36" -X POST -H "Content-Type: application/x-www-form-urlencoded" --data "product_permalink=test&license_key=test" https://app.radzen.com/v2/licenses/verify

```

Whichever of these returns `<!--samlch…` instead of the JSON tells us where the interception happens. In both cases the fix is on the network side: IT needs to exempt `app.radzen.com` from SAML authentication for non-browser clients, or allow Blazor Studio to bypass the proxy for that host. The key only has to be validated once, so doing it from a network without the proxy (home network, phone hotspot) also works.

---

<div class="post-metadata">

**Author:** ![Kield](https://forum.radzen.com/letter_avatar_proxy/v4/letter/k/dec6dc/32.png) [@Kield](https://forum.radzen.com/u/Kield)\
**Post date:** [November 3, 2026, 8:26am UTC](https://forum.radzen.com/t/license-key-issue/21760/10 "2026-11-03T08:26:34Z")

</div>

Okay, the first one returned an IP address:[http://185.46.212.88/](http://185.46.212.88/) The others Json: {"success":false,"message":"License key not found"}

Still I will contact our IT department. Just to be sure...

---

<div class="post-metadata">

**Author:** ![Kield](https://forum.radzen.com/letter_avatar_proxy/v4/letter/k/dec6dc/32.png) [@Kield](https://forum.radzen.com/u/Kield)\
**Post date:** [November 3, 2026, 9:11am UTC](https://forum.radzen.com/t/license-key-issue/21760/11 "2026-11-03T09:11:12Z")

</div>

Strange. It works now?? Suddenly I could download the latest update and install it without any problems. Nothing is changed at my end 🤔

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<div class="post-metadata">

**Author:** ![enchev](https://forum.radzen.com/user_avatar/forum.radzen.com/enchev/32/16_2.png) [@enchev](https://forum.radzen.com/u/enchev)\
**Post date:** [November 3, 2026, 12:38pm UTC](https://forum.radzen.com/t/license-key-issue/21760/12 "2026-11-03T12:38:40Z")

</div>

Glad it works. The update is most likely a coincidence: nothing changed in the license validation or in how Blazor Studio reaches the network between the two versions.

What fits all your observations is the proxy at 185.46.212.88. Gateways that authenticate through SAML remember a signed-in user by machine or IP address for a while. When that session expires, the next request from a client that is not a browser, such as Blazor Studio, gets the SAML sign-in page, which is what the first screenshot showed. Once you sign in again from a browser (opening any site through the proxy is enough, often it happens silently), the gateway associates your machine with you again and lets Blazor Studio's requests through. By the time you ran the tests the session had already been refreshed, so the request through the proxy also returned JSON.

If the error comes back, open a page in your browser first and then validate the key again. Asking IT to exempt `app.radzen.com` from SAML authentication will make it go away for good.