constantly receiving an error undefined function or variable z

No matter what I type into MATLAB, I receive an error:

Undefined function or variable z

This error initially occurred after I tried to define:

>> z=2

(z did not appear in my workspace)

Now it occurs even when I try things that do not include a 'z':

>> 2*2
>> x=2
>> restoredefaultcache
>> rehash toolboxcache

Answer 1

[MathWorks Support Team]

Restart MATLAB to clear any association with the function or variable 'z'.