It seems some setting of dynamic widgets is creating problems, so please check setting of dynamice widgets.
And also you are using outdated version of celestial theme, so please update to latest version 3.0.2.
If you got any problems on this please don’t hesitate to reach back out to us. We will be more than glad to assist you
Note: Please take a backup of your site before proceeding so you will be in position to take action when disaster strikes.
. Normally we use duplicator plugin to make a backup.https://wordpress.org/plugins/duplicator/.