errors on install

This error appears at the top when I activate the plugin.

Notice: register_uninstall_hook was called incorrectly. Only a static class method or function can be used in an uninstall hook. Please see Debugging in WordPress for more information. (This message was added in version 3.1.) in /home/adamant/public_html_blog/wp-includes/functions.php on line 3897

And under the Plugins header:

The plugin generated 416 characters of unexpected output during activation. If you notice “headers already sent” messages, problems with syndication feeds or other issues, try deactivating or removing this plugin.

https://www.ads-software.com/plugins/wp-theme-test/