Cannot connect the output of the MATLAB function to mux and the subsystem, why?

I cannot connect the output of the MATLAB function to mux and the subsystem at the same time.

How can I solve this issue?

[TAB]

It is possible in my Matlab R2015b version.

Which version of Matlab are you using ?

[Canberk Suat Gurel]

I am using R2017b version.

[Canberk Suat Gurel]

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By the way, I am receiving this Error message almost every 2 to 3 days (I use MATLAB daily). I sent the error report to MathWorks and I am waiting for a response.