Hi spirish,
The plugin isn’t broken with https enabled. If you’re getting that error, it means you have a configuration error in your main settings page.
On the main WordPress settings page (“General Settings”), both URL fields (“WordPress Address (URL)” and “Site Address (URL)”) need to have the same URL scheme (“https://” or “https://”) – they have to match.
That error message you are getting (and subsequent deactivation) from WP-SpamShield is happening because it is doing error checking, and found the problem in your settings: One URL is “https://” and one is “https://”, which will present problems for your site, and prevent certain things from working, including WP-SpamShield. If you fix that error in the settings (so both should start with “https://”)…everything will work again.
If you have any further issues or questions, please submit a support request at the WP-SpamShield Support Form (our main support venue), and we’ll be happy to help you out.
– Scott