Cathal1 "sign into my virgin media and at the bottom of the page it says email"
So you are using VM webmail - you can access it either via the "My Virgin Media" account or by signing into webmail directly. Either route takes you to VM's webmail service on the VM website.
I must admit I held off replying earlier to see if there were other reports of this happening with webmail. It seems not!
I have only ever seen the black screen & "message has no content" reported by people using MS Outlook or the IOS mail app to access non VM email accounts. Sadly, there does not seem to have ever been a conclusive solution reported.
It might be worth checking VM's service status in your area https://www.virginmedia.com/help/check/status/result to see if there are network issues in your area. But to be honest if you are using webmail I cannot really see network issues as being the cause.
I do have a couple of other suggestions though.
Looking through your posting history I see that you have a second VM email account. I think there was some confusion as to which was the primary account.
If I was in your position I would carry out the same test- sending a test email from your other VM email account to that email account - to see if it gives the same black screen result.
If it emails sent from and to your other VM account display correctly then it suggests the issue is with the your first VM email account that is currently causing it to show a black screen.
If your alternative VM email account also displays a black screen it could suggest the issue may be related to your VM broadband, or possibly to an issue with your browser.
It would be worth signing into webmail using a different browser to check whether it is a browser specific issue.
If you try those tests it may help to identify where the problem lies. That will be at least be one step forward.
Coenoby