What can I do to avoid the following error with mupadmex ?

I am experiencing the following error. Maybe someone can help. I am on a macOS Sierra version 10.12.4 and using Matlab 2017a.

>> syms x
Error using mupadmex
Error in MuPAD command:

Error in sym>cell2ref (line 1281)
S = mupadmex(y);

Error in sym>tomupad (line 1219)
    S = cell2ref(numeric2cellstr(x));

Error in sym (line 179)
                S.s = tomupad(x);

Error in syms (line 144)
toDefine = sym(zeros(1, 0));

Answer 1

[Varun Gunda]

Executing "which -all sym" reveals if there is a custom file with the same name "sym", which is causing this error. Renaming the custom file resolved the issue.

[Matthias]

Thank you for your response. Unfortunately, that is not the cause of the problem. I get

>> which -all syms
/Volumes/MacintoshHD2/Software/MATLAB_R2017a.app/toolbox/symbolic/symbolic/syms.m
>> which -all sym
/Volumes/MacintoshHD2/Software/MATLAB_R2017a.app/toolbox/symbolic/symbolic/@sym/sym.m  % sym constructor
>> which -all mupadmex
/Volumes/MacintoshHD2/Software/MATLAB_R2017a.app/toolbox/symbolic/symbolic/mupadmex.mexmaci64

[Walter Roberson]

You have an installation problem of some sort.

What shows up for

!otool -L /Volumes/MacintoshHD2/Software/MATLAB_R2017a.app/toolbox/symbolic/symbolic/mupadmex.mexmaci64

?