Cause: You copied the key incorrectly, or it has expired. Fix: Copy the key exactly. Do not include spaces. Log into your Plesk account portal to ensure the trial hasn't time-expired.
If you have already installed an unlicensed version of Plesk (the installer comes without a key), you can add a trial key via SSH: plesk trial key
plesk bin license --install KEY
Replace KEY with the trial code you received from the Plesk website. Cause: You copied the key incorrectly, or it has expired
Once your 14‑day trial expires, Plesk allows you to install a specific extension called “Plesk 360 Monitoring” (or similar trial‑extending tools) which, in some versions, can trigger a one‑time trial extension of another 14 days — provided the server hostname and IP haven’t been used for a paid license before. Replace KEY with the trial code you received
How it works:
Go to Extensions → search for “Trial” or “License Management” → some partner extensions (e.g., from hosting providers like OVH, Hetzner) include backend scripts that re‑generate a temporary key for evaluation purposes.