administrator permissions on a SSAS database

I had a third party company coming over and building ssas databases to produce reports.

They did, but now the DBA wants to have a look but I haven't got permissions, to even see those databases, as you can see on the picture below.

Can I grant myself administrator permissions?

I am system administrator. there is a AD group called SQLDBA and

When right-cliking on the server-properties-security-Add-
then adding my AD group SQLDBA it says I don't have the permissions to alter the server object as you can see on the picture below.

I had previously added that sqldba AD group as an administrator to that box.

TITLE: Microsoft SQL Server Management Studio

Either the 'mycompany\MMiorelli' user does not have permission to alter the 'myserver\instance' object, or the object does not exist.
(Microsoft.AnalysisServices.AppLocal.Core)

BUTTONS:

OK

from the comments by Denis Rubashkin


Try to use "Run as administrator" when running SSMS, it solved the
same problem for me

and that worked for me too.

to run ssms as and administrator press the shift and right click on the ssms icon and that will give the options below:

StackExchange Database Administrators Q#206771, answer score: 5