Fieldtrip: ft_timelockstatistics error

bst_ft_init
[ft_ver, ft_path] = ft_version
BST> FieldTrip install: C:\Program Files\MATLAB\R2016a\toolbox\fieldtrip-20200423\fieldtrip-20200423
Warning: removing "C:\Program
Files\MATLAB\R2016a\toolbox\fieldtrip-20200423\fieldtrip-20200423\compat\matlablt2016b" from your path,
see Redirecting…
In contains (line 29)
In ft_hastoolbox>is_subdir_in_fieldtrip_path (line 634)
In ft_hastoolbox (line 437)
In ft_defaults (line 249)
In bst_ft_init (line 93)

ans =

 1

Warning: removing "C:\Program
Files\MATLAB\R2016a\toolbox\fieldtrip-20200423\fieldtrip-20200423\compat\matlablt2017b" from your path,
see Redirecting…

In isfolder (line 28)
In ft_version (line 64)
Error using feval
Undefined function 'isfolder' for input arguments of type 'char'.

Error in isfolder (line 34)
[varargout{1:nargout}] = feval(mfilename, varargin{:});

Error in ft_version (line 64)
issvn = isfolder(fullfile(ftpath, '.svn'));

Here are what I've got. I guess I should follow the instruction to remove the corresponding folder from the path?