datastore function - new error not seen before

A month ago, I was able to run this script. The folder contain 900+ csv files. But now I can't, and couldn't figure out why.

dsFull = datastore("C:\Data\04 CSV\100 200");

%Converting all variables into '%q' for string as R2020b version automatically
%assign data type according to the first row creating error when readall.
dsFull.VariableNames
dsFull.TextscanFormats = {'%q' '%q' '%q' '%q' '%q' '%q' '%q'}

%create Cardiology Discharge Summary table name cds
cds = readall(dsFull);

I received this error:

Maximum recursion limit of 500 reached.

Error in coder.const (line 25)

[varargout{:}] = feval(varargin{1}, varargin{2:end});

Caused by:

Maximum recursion limit of 500 reached.

Unrecognized function or variable 'eml_numfields'.

Error in fieldnames>loc_fnames (line 36)

n = eml_numfields(s);

Error in fieldnames (line 25)

names = loc_fnames(s);

Error in weboptions>setInputs (line 650)

names = fieldnames(inputs);

Error in weboptions (line 378)

options = setInputs(options, inputs);

Error in matlab.internal.doc.updateConnectorDocroot (line 3)

options = weboptions('RequestMethod','post', ...

Unrecognized function or variable 'eml_numfields'.

Error in fieldnames>loc_fnames (line 36)

n = eml_numfields(s);

Error in fieldnames (line 25)

names = loc_fnames(s);

Error in weboptions>setInputs (line 650)

names = fieldnames(inputs);

Error in weboptions (line 378)

options = setInputs(options, inputs);

Error in matlab.internal.doc.updateConnectorDocroot (line 3)

options = weboptions('RequestMethod','post', ...

Maximum recursion limit of 500 reached.

Error in coder.const (line 25)

[varargout{:}] = feval(varargin{1}, varargin{2:end});

Caused by:

Maximum recursion limit of 500 reached.

Maximum recursion limit of 500 reached.

Error in coder.const (line 25)

[varargout{:}] = feval(varargin{1}, varargin{2:end});

Caused by:

Maximum recursion limit of 500 reached.

[KSSV]

Try:

set(0, 'RecursionLimit', 1000);

[Stephen23]

Do NOT change the recursion limit, doing so will NOT fix this problem.

It looks like you (or a toolbox you have installed) has shadowed a function name, which causes the recursion.

Judging by the error message, a likely candidate is FIELDNAMES. Please show us the complete output of this command:

which fieldnames -all

and you might as well show us these too:

which weboptions -all
which datastore -all
which readall -all

[Chun Siong Soon]

I'm facing a similar problem. There are various manifestations, but eml_XXX errors keep popping up.

Matlab is no longer useable for me. I completely reinstalled a newer version and it happened again.

Even basic commands like tic, help, pwd leads to errors. here are some snippets:

============================

>> help fullfile

Warning: The following error was caught while executing 'matlab.internal.help.helpProcess' class destructor:

Error using char (line 16)

For code generation, cell array inputs to 'char' are not supported.

Error in matlab.internal.help.makeDualCommand (line 11)

dualCommand = char(join([command, varargin], " "));

Error in matlab.internal.help.helpProcess/displayHelp (line 11)

searchMessage = getString(message('MATLAB:helpUtils:displayHelp:SearchMessageWithLinks',

erase(matlab.internal.help.makeDualCommand('docsearch', hp.topic), '"')));

Error in matlab.internal.help.helpProcess/delete (line 102)

disp(hp.displayHelp);

Error in help (line 73)

end

> In help (line 73)

=======================================

Warning: The following error was caught while executing 'matlab.internal.help.helpProcess' class destructor:

Error using char (line 16)

For code generation, cell array inputs to 'char' are not supported.

Error in matlab.internal.help.makeDualCommand (line 11)

dualCommand = char(join([command, varargin], " "));

Error in matlab.internal.help.helpProcess/displayHelp (line 11)

searchMessage = getString(message('MATLAB:helpUtils:displayHelp:SearchMessageWithLinks',

erase(matlab.internal.help.makeDualCommand('docsearch', hp.topic), '"')));

Error in matlab.internal.help.helpProcess/delete (line 102)

disp(hp.displayHelp);

Error in help (line 73)

end

> In help (line 73)