HRmatlab - You can try using the "exist" function to check if the files/folder are detected on MATLAB search path. If the files are detected, this behavior could possibly result due to corrupted or missing files.
If the files are not detected, try navigating to the folder location in MATLAB and execute the "demdataui" app to further make sure. If "demdataui" was able to detect the files this way, you can add the current working directory to the path using the following commands:
addpath(pwd)
savepath()
