Command line help fails, reports "Error using append Too many input arguments"

Example, requesting just "help" with no arguments ...

>> help
Warning: The following error was caught while executing 'matlab.internal.help.helpProcess' class destructor:
Error using append
Too many input arguments.
Error in matlab.internal.help.createMatlabLink (line 5)
link = append('', linkText, '');
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Error in matlab.internal.help.createMatlabCommandWithTitle (line 3)
link = matlab.internal.help.createMatlabLink(action, item, message);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Error in matlab.internal.help.helpProcess/displayHelp (line 19)
searchCommand = matlab.internal.help.createMatlabCommandWithTitle(hp.wantHyperlinks, searchMessage, "docsearch", hp.topic);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Error in matlab.internal.help.helpProcess/delete (line 95)
disp(hp.displayHelp);
^^^^^^^^^^^^^^
Error in help (line 29)
end
^ 
> In help (line 29) 
>> 

[Meg Noah]

What command was given right before the command help? In R2024b, it appears to execute help on the last function/method that was run.

Answer 1

[Walter Roberson]

You have a third-party append.m that is interfering with the Mathworks append()

which -all append

/MATLAB/toolbox/matlab/strfun/append.m
/MATLAB/toolbox/control/ctrlobsolete/@double/append.m                                                                      % double method
append is a built-in method                                                                                                % string method
/MATLAB/toolbox/matlab/timeseries/@timeseries/append.m                                                                     % timeseries method
append is a Java method                                                                                                    % com.mathworks.fileutils.MatlabPath method
append is a built-in method                                                                                                % matlab.automation.Verbosity method
append is a built-in method                                                                                                % matlab.unittest.internal.fixtures.FolderScope method
/MATLAB/toolbox/matlab/testframework/unittest/core/+matlab/+unittest/+plugins/+plugindata/ResultDetails.m                  % matlab.unittest.plugins.plugindata.ResultDetails method
/MATLAB/toolbox/matlab/external/interfaces/webservices/http/+matlab/+net/+http/+io/ContentConsumer.m                       % matlab.net.http.io.ContentConsumer method
/MATLAB/toolbox/matlab/testframework/unittest/core/+matlab/+unittest/+internal/+diagnostics/CompositeConditionsSupplier.m  % matlab.unittest.internal.diagnostics.CompositeConditionsSupplier method
append is a built-in method                                                                                                % py.list method
/MATLAB/toolbox/mbc/mbcdata/@cgoppoint/append.m                                                                            % cgoppoint method
/MATLAB/toolbox/mbc/mbcdesign/@designdev/append.m                                                                          % designdev method
/MATLAB/toolbox/mbc/mbcguitools/@xreglistctrl/append.m                                                                     % xreglistctrl method
/MATLAB/toolbox/mbc/mbctools/@sweepset/append.m                                                                            % sweepset method
/MATLAB/toolbox/risk/risk/@esbacktest/append.m                                                                             % esbacktest method
/MATLAB/toolbox/risk/risk/@varbacktest/append.m                                                                            % varbacktest method
/MATLAB/toolbox/shared/controllib/engine/@InputOutputModel/append.m                                                        % InputOutputModel method

I predict that something else will show up before toolbox/matlab/strfun/append.m

[Alan]

Bingo. That was my problem. Thanks!