BuddyPress.org

I’ve migrated a website from another host, and am now trying to activate the relevant plugins including BuddyPress. However, when I do activate BuddyPress, I get the following errors showing when WP debug is on:

<b>Notice</b>:  Constant BUDDYBLOG_ARCHIVE_SLUG already defined in <b>/home/makers/public_html/wp-content/plugins/bp-custom.php</b> on line <b>10</b><br />
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<b>Strict Standards</b>:  Declaration of BuddyBlogCoreComponent::setup_globals() should be compatible with BP_Component::setup_globals($args = Array) in <b>.../wp-content/plugins/buddyblog/buddyblog-loader.php</b> on line <b>0</b><br />
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<b>Strict Standards</b>:  Declaration of BuddyBlogCoreComponent::includes() should be compatible with BP_Component::includes($includes = Array) in <b>.../wp-content/plugins/buddyblog/buddyblog-loader.php</b> on line <b>0</b><br />
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<b>Strict Standards</b>:  Declaration of BuddyBlogCoreComponent::setup_nav() should be compatible with BP_Component::setup_nav($main_nav = Array, $sub_nav = Array) in <b>.../wp-content/plugins/buddyblog/buddyblog-loader.php</b> on line <b>0</b><br />
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<b>Strict Standards</b>:  Declaration of BuddyBlogCoreComponent::setup_admin_bar() should be compatible with BP_Component::setup_admin_bar($wp_admin_nav = Array) in <b>/.../wp-content/plugins/buddyblog/buddyblog-loader.php</b> on line <b>0</b><br />

Any ideas why this is happening, & how the issues can be rectified?