--- title: "Sync server TLS 1.2 | Lansweeper Classic" slug: "cloud-requirement-sync-server-tls-12" description: "Resolve the sync server TLS 1.2 check when linking Lansweeper Classic to a Lansweeper Platform site. Learn why TLS 1.2 is required and how to enable it." tags: ["Lansweeper Classic", "Getting started", "Hybrid"] updated: 2026-06-25T19:51:24Z published: 2026-06-25T19:51:24Z canonical: "docs.lansweeper.com/cloud-requirement-sync-server-tls-12" --- > ## Documentation Index > Fetch the complete documentation index at: https://docs.lansweeper.com/llms.txt > Use this file to discover all available pages before exploring further. # Sync server TLS 1.2 When you link a Lansweeper Classic installation to a [Lansweeper Platform](/docs/what-is-lansweeper) site, one of the [prerequisite checks](/classic/docs/cloud-linking-requirements) confirms that your sync server has TLS 1.2 enabled. Your sync server is the scanning server you select to sync with Lansweeper Platform. ## Why this check runs To secure communication between your installation and Lansweeper Platform, the connection uses the TLS 1.2 cryptographic protocol. If your sync server doesn't have TLS 1.2 enabled, communication with the Platform fails. Computers running a modern operating system usually have TLS 1.2 enabled by default. ## Resolve a failed check If the sync server TLS 1.2 check fails, enable TLS 1.2 on the machine hosting your sync server. You can find instructions online and in Microsoft's documentation. Registry edits can break the machine Edit TLS settings in the machine's registry carefully. Incorrect changes can stop the machine from working. When all prerequisites pass, you can [link your installation to a site](/classic/docs/link-lansweeper-classic-with-lansweeper-platform).