--- title: "Activation Issue: The server could not be reached. Details: N2 C0" description: How to resolve the N6 C0 activation issue --- [Skip to content](https://support.keyshot.com/en/knowledge-base/activation-issue-the-server-could-not-be-reached.-details-n2-c0#main-content) English Show submenu for translations ![KeyShot](https://support.keyshot.com/hs-fs/hubfs/keyshot-logo-blk-3d.png?height=40&name=keyshot-logo-blk-3d.png) - [Support Home Page](https://www.keyshot.com/support/) - [Sign Out](https://support.keyshot.com/_hcms/mem/logout) Open main navigation Close main navigation - [Support Home Page](https://www.keyshot.com/support/) - [Sign Out](https://support.keyshot.com/_hcms/mem/logout) - English Show submenu for translations - [My Inbox](https://support.keyshot.com/tickets-view) [My Inbox](https://support.keyshot.com/tickets-view?hsLang=en) Tell us what's happening - There are no suggestions because the search field is empty. 1. [Support Knowledge Base](https://support.keyshot.com/en/knowledge-base?hsLang=en) 2. [License Support](https://support.keyshot.com/en/knowledge-base/license-support?hsLang=en) 3. [Subscription](https://support.keyshot.com/en/knowledge-base/license-support?hsLang=en#subscription) # Activation Issue: The server could not be reached. Details: N2 C0 ## How to resolve the N6 C0 activation issue ### Issue When trying to activate KeyShot, you may get the following error. The server could not be reached. Details: N2 C0 ![](https://support.keyshot.com/hs-fs/hubfs/image-png-Mar-30-2026-01-50-32-1058-PM.png?width=498&height=389&name=image-png-Mar-30-2026-01-50-32-1058-PM.png) ### Environment Details - KeyShot ### Cause - The error N2C0 means that the remote server closed the connection prematurely, before the entire reply was received. This usually points towards a connection issue. This is most likely due to the Firewall settings. ### Resolution First,  Could you please add the following KeyShot URLs to the Firewall Whitelist for the organization and bypass them from TLS inspections? • \*.keyshot.io • \*.keyshot.com • [https://login-configuration.keyshot.com](https://login-configuration.keyshot.com/) • [https://login.keyshot.com](https://login.keyshot.com/) • [https://app.keyshot.com](https://app.keyshot.com/) • [https://cognito-idp.us-east-2.amazonaws.com](https://cognito-idp.us-east-2.amazonaws.com/) **Note**: Contact your Network IT department to assist in adding these entries. If the error persist, please try the following: Could you please try to rule out firewall blocks: Press Win+R → wf.msc → Outbound Rules.Look for any Block rule targeting KeyShot/KeyShot Studio (or its “Auth/Login” helper keyshot\_auth\_handler.exe for KeyShot 2025.3 or prior) and disable it. Also check Windows Defender Firewall Properties → \[Domain/Private/Public\] Profile → Outbound connections is set to Allow (default). If the proxy is using SSL inspection, please make sure that the URLs mentioned above are excluded from the inspection/bypass ed. Security suites (Kaspersky, Bitdefender, ESET, etc.) with “HTTPS scanning” can break TLS and cause timeouts. Temporarily disable SSL inspection/HTTPS scanning and re-test the issue. Just to be safe, please ensure Windows date/time and time zone are correct, since a bad clock might cause TLS failures/timeouts. 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