Scan Engine Error: The signature on the request to start a scan is invalid. Plea

It was because I changed the wp-admin URL. Removing this plugin and the scans started to work again.

Thanks for letting us know the outcome @exactprecisions.

If it’s relevant to your original request, we’ve had to add “Change wp-admin login (change-wp-admin-login)” to our incompatibility list as it causes this error message to appear across other customer sites.

Thanks,
Peter.