error when connecting powerbi to analyssis services multidimensional model

In my company we have a host of SSAS models running that we would like to enable in powerbi. we have established the data gateway and it works very well.

The issue is that for some of the cubes we have on a server, we get an error when connecting in powerbi. Other cubes on the same server are working perfectly. The error the users get are:

An error occurred while loading the model for the item or data source 'QuerySystemError'. Verify that the connection information is correct and that you have permissions to access the data source.

Do anyone know what this error can be related to? im wondering if it because the compatability level of some of the cubes are too old and would have to be updated