run() command does not run .m file already in the directory, showing [Error using evalin Undefined function or variable]

In a directory @tree, I have a matlab file as Constructing_hierarchy_tree.m. when i am inside the directory and I am typing the command dir, it shows that this file is inside this directory but when i do run('Constructing_hierarchy_tree.m') in the command window. it is showing me

>> run('Constructing_hierarchy_tree.m'); Error using evalin Undefined function or variable 'Constructing_hierarchy_tree'.

Error in run (line 63) evalin('caller', [script ';']);

I searched for help in other matlab forum questions and i tried couple things but it did not work. any help is highly appreciated. please no rude comment.

[Stephen23]

Please run this command and tell us exactly what it prints:

which Constructing_hierarchy_tree -all