This is an old post, but I'm having the exact same issue in MATLAB 2012a. Replace the number 1 with 6, and his files with mine and the message is the same.
I know this is a case where the actual error is NOT where MATLAB is indicating the error is. I had a model that was working fine with no errors (but not modeling correctly). I replaced an existing Simulink subsystem in the model with a custom S-Function. When I ran with the new S-Function, I got this error, but the demux in question was UPSTREAM of the new S-Function. As a double check I put the old subsystem back in place and everything ran fine. It is truly bizarre to me.
"Johnny Sandaire" wrote in message <h37lu5$ke$1@fred.mathworks.com>...
> Greetings,
>
> I followed the process to develop a FIS that works; however, when I tried to execute it in a simulink environment, I get the following errors:
>
> Invalid setting for input port dimensions of _mamdani_Sim/Fuzzy Logic Controller with Ruleviewer/Fuzzy Logic Controller/FIS Wizard/Demux'. The dimensions are being set to 1. This is not valid because the total number of input and output elements are not the same.
>
> and
>
> Error in port widths or dimensions. Output port 1 of _mamdani_Sim/Fuzzy Logic Controller with Ruleviewer/Fuzzy Logic Controller/FIS Wizard/In1' is a one dimensional vector with 1 elements.
>
> I am not sure how to fix this issue. Does anyone has any insight on how to get this simulink working?
>
> Tks,
>
> Johnny