Deactivating the Slideshow Gallery mucks up my site

I no longer have need for the Slideshow Gallery pluging. However, when I tried to deactivate it, I got a series of error codes:
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Notice: WP_User->id was called with an argument that is deprecated since version 2.1! Use WP_User->ID instead. in/home/eclect01/public_html/wp-includes/functions.php on line 3508

Warning: Cannot modify header information – headers already sent by (output started at /home/eclect01/public_html/wp-includes/functions.php:3508) in /home/eclect01/public_html/wp-content/plugins/wp-super-cache/wp-cache-phase2.php on line 60

Notice: register_sidebar_widget is deprecated since version 2.8! Use wp_register_sidebar_widget() instead. in/home/eclect01/public_html/wp-includes/functions.php on line 3391

Notice: register_widget_control is deprecated since version 2.8! Use wp_register_widget_control() instead. in/home/eclect01/public_html/wp-includes/functions.php on line 3391
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It also made a hash out of the plugins page in the dashboard, displaying it very oddly. I’d do a screenshot but it’s too large and sprawling. The left side bar has each button tripled in size and the right sidebar seems to large so gets shoved to the bottom.

Reactivating it solved the problem.

I am having some other issues with Jetpack so this may be somehow related. If you have any advice, I’d appreciate it.

https://www.ads-software.com/plugins/slideshow-gallery/