exp function no longer working.

Hello, I'm suddenly getting an error plotting a Gaussian function through the exp command:

 fitGaus =  a*exp(-0.5*((xdataFine-b)/c).^2)+d;

The only thing I have done is add all my matlab programs ever created to the path using the add path tool (2019b0

unrecognised function or variable 'exp'

I have checked the exp function:

>> which exp
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\elfun\@double\exp)  % double method

and opening this gives:

%EXP    Exponential.
%   EXP(X) is the exponential of the elements of X, e to the X.
%   For complex Z=X+i*Y, EXP(Z) = EXP(X)*(COS(Y)+i*SIN(Y)).
%
%   See also EXPM1, LOG, LOG10, EXPM, EXPINT.

%   Copyright 1984-2005 The MathWorks, Inc.
%   Built-in function.

Is it possible I have another exp somewhere and if so how can i reset it?

Thnaks

Jason

[Walter Roberson]

restoredefaultpath

[Jason]

Thankyou