Before I made the switch to Pulse I never had that many experience with Analysis Services cubes (neither Multidimensional nor Tabular). After making the switch from integration (with Microsoft BizTalk) I did start out with Power Pivot at ADA, on which I also wrote a few blog posts, about CALCULATE, which is The Queen of all DAX functions according to Marco and Alberto. But for the other projects we did at ADA it just wasn't a direction we took, maybe also due to the lack of experience with SSAS.
The last months I got involved more in Multidimensional as well as Tabular and therefore also ran into other issues lately, the latest I will describe here.
During deployment of an SSAS multidimensional cube in Visual Studio I received a very descriptive error message saying (in Dutch): "The following system error occurred:". And that was it. No description of any kind. The output window of Visual Studio did mention some long error number, but that turned out to be not very useful (read: useless).
Also, when a key user wanted to change the rights of a cube he also received the same error. He was trying to give a specific person (UserA) rights to the Purchase role. Although UserA could be added perfectly fine to the Administrator role for example, adding UserA to this role would fail with this error.
As you can see in the screenshot of my Role Properties window below there is a SID showing instead of a user name, but in the Properties window of the key user the user name was correctly displayed. After seeing this SID I immediately thought of a user that was no longer valid/active in AD, but let's see what steps I took to come this far in the first place.
The first thing I tried was ignoring the error in VS and continue the deployment. That worked but I was unsure what gave me the error and if the deployment itself was properly done. I also noted that every cube gave this error in deployment, so it wasn't a cube-specific thing.
Then my colleague Ron pointed me to the possibility of deploying the .asdatabase-file, which is located in the bin directory of the solution.
This .asdatabase-file is like the ispac-file for SSIS, it's the output of the project when built in SSDT. You can either start the Analysis Services Deployment Wizard or double click the .asdatabase-file. The Microsoft.AnalysisServices.Deployment.exe that is used to start the wizard can be found in the following location, where 120 stands for my SQL version (2014).
After going through the first steps of the wizard brings me at the Options for Partitions and Roles:
The important part here is the bottom selection: "Retain roles and members". This means existing roles and role members in the destination database are retained and no new roles are deployed. After having selected this option the deployment succeeded without any errors.
TL;DR: The Solution
Delete the SID from the Role Properties. Also make sure to delete it, or check that it doesn't exist, from the roles Membership tab in Visual Studio.
After the cleanup I was able to add UserA to the Role again and also the deployment of the project in Visual Studio was flawless.