Unable to set OptimOptions for Solvers in Curvefitting

I have a multivariable non-linear regression code which was working fine in Matlab 2014b. Now setting the options for lsqcurvefit (or any fit) throws an error in Matlab 2020a. I am following the documentation. Does any toolbox need to be activated for this code snippet?

options = optimoptions('lsqcurvefit');

% Throws this error:
% Error using optimoptions (line 124)
% Empty keys are not allowed in this container.

[Ameer Hamza]

Can you show the output of

which optimoptions -all

[hisenbug]

@Ameer This is what I get:

C:\Program Files\MATLAB\R2020a\toolbox\shared\optimlib\optimoptions.m

[Ameer Hamza]

This output indicates that MATLAB is using the correct file. This is quite a strange error. I tried it on R2020a, and it works fine. Is the error message in your question complete?

[hisenbug]

Yeah, I tried it again right after restarting Matlab and still I get the same error.

I am eligibile for the R2020b upgrade. I'll try doing that now.

[hisenbug]

@Ameer I found this solution: https://www.mathworks.com/matlabcentral/answers/512878-optimoptions-error-empty-keys-are-not-allowed-in-this-container-no-number-given

Should have searched the error first!

Thanks.

[Ameer Hamza]

Glad that it worked out finally. Did you reinstall the optimization toolboxes?

[hisenbug]

I installed R2020b with all Optimization Toolboxes. That worked.