There can be several different causes of this particular error message.

Always check to see what type or types of licenses they using. For example, a standalone or License Manager.

For issues that only apply to License Manager, you’ll see (LM) in the title of the article. The other links apply to a standalone set-up or both License Manager and standalone licenses.

See links below for possible solutions to this problem. The list can help determine the issue.

• Error: "A protection device or license is required" (Remote Desktop Connection) (Pervasive)
• Error: "A protection device or license is required" (LM) (LSFORCEHOST environment variable) (Pervasive)
• Error: "A protection device or license is required" (Computer name was changed or computer was imaged) (Pervasive)
• Error: "A protection device or license is required" (LM) (Router or Switch not forwarding LM network packets) (Pervasive)
• Error: "A protection device or license is required" (LM) (A firewall is blocking the connection) (Pervasive)
• Error: "A protection device or license is required" (LM) server lost its licenses) (Pervasive)
• Error: "A protection device or license is required" (LM) license code is missing) (Pervasive)
• Error: "A protection device or license is required to use Timberline applications" after installing Windows 10 version 1803. (Pervasive)