WPMUDEV Dashboard update to v4.0.4 causes 500 - Internal Server Error

Dear Support,

I am experiecing endless problems trying to update to WPMUDEV Dashboard v4.0.4. This is really impacting on my business and causing me a lot of problems.

I am experiencing an error 500 - Internal Server Error. This appears after installing the plugin and then navigating back to the plugins list. I have now lost the ability to log into the admin function.

I have never had an error like this before with any other plugins.

Please advise ASAP.

Kind regards,
Will