Thank you for the credentials, did this happen after a Wordpress update?
It seems this is an issue with the Wordpress itself because even if you used the default theme you’ll still get these errors.
Please do a test for a plugin conflict. You can do this by deactivating all third-party plugins, and seeing if the problem remains. If it’s fixed, you’ll know a plugin caused the problem, and you can narrow down which one by reactivating them one at a time.
If that did not work, would you mind reinstall a clean version of WordPress? You can follow the guide provided here.
Let us know how it goes,