Having error after host migration

Hello I migrated our site from our old host acct and now we aren't able to view our dashboard and it displays the following message:

Fatal error: Call to undefined function switch_to_blog() in /home/egg1212/public_html/kozofineartmaterials.com/wp-content/plugins/ultimate-branding/ultimate-branding-files/modules/favicons.php on line 262

not sure how to address this any help would be greatly appreciated thanks.