Site not loading after latest Wordpress update

Our site is not loading, I’m sure it coincides with the latest wordpress update from late last week. I have the latest theme update and plugins. It won’t let me update to the latest Visual Composer or Go Pricing plugins - I have versions versions 5.0 and 3.33 of these. I have also tried de-activating these deleting them and re-installing them but it still won’t load. Any ideas please?
Many thanks

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