License activation: "Key Is Invalid" error when using a license key

Symptoms

The error "Key is invalid" is displayed when attempting to activate a JetBrains product using a license key.

Environment

• Customer type: All customers
• Region: All regions
• Product: All paid IDE licenses

Cause 

The license is not being activated using a supported activation method. 
JetBrains products can be activated using JetBrains Account credentials or, where applicable, an offline activation code.

Resolution

1. Sign in to the IDE using the JetBrains Account credentials associated with the license
2. If an offline activation is required, use an offline activation code instead of a license key
3. If the license cannot be located or the error persists, contact Sales Support and provide:
   a. The order number, invoice number, or license ID
   b. Screenshot of the error message