Unable to Access Dynatrace Managed Tenant

[Nicky23]

I’ve been added as an administrator to a Dynatrace Managed environment, but I’m unable to access the tenant. I’ve confirmed that my user account has administrator permissions, but every time I try to log in, I either encounter an error or can’t access the tenant. Could someone help me identify the possible reasons for this issue? I would really appreciate your guidance.

[MostafaHussein]

I recommend to open ticket with DT support.

BR,
Mostafa Hussein.

[ChadTurner]

Are there any other users that are Admins that can check your account? If you are set as SSO you might not be able to access the Support portal.... to which the last resort would be to hit up your account executive as they can put in the support ticket for you. 
Do you know if your Organization updated the SSO Cert? Do you have a back door account that will allow you to log in?

[fstekelenburg]

I agree with Chad it looks like a permission/account issue.
You should at least be able to connect to the Cluster Management Console (CMC):
https://<address-of-the-managed-environment>/cmc