A FortiWeb can be configured to join a Security Fabric through the root or downstream FortiGate.
When attempting to upload the license to a newly deployed FortiWeb-VM, the message "License has been detected as an invalid copy, please upload a new license." may been seen.

The exact message may vary depending on the firmware version.

This article is for FortiWeb-VM only, not physical FortiWeb appliances.

A common cause of this issue is the number of virtual CPU cores configured on the FortiWeb-VM virtual machine instance does not match the number of CPUs purchased on the FortiWeb-VM license.  Once the number of assigned virtual CPU cores matches the license, the license will be able to be successfully uploaded to the FortiWeb.

An example is shown below of a FortiWeb deployed on VMware ESXi server.

The product model will show the number of CPU licenses that were purchased with the FortiWeb-VM.  This can be seen on the Fortinet Customer Service & Support web portal by navigating to Manage/View Products > Asset.  In this example the FortiWeb-VM was purchased with a 1 CPU license.

However, the ESXi server has 2 virtual CPU cores configured. Trying to upload the license file will not work until the number of virtual sockets is decreased to 1.