Error using DEM visualization

[Tejaswi-06-24]

hello community,
When i selected the option: Select DEM -> Download DEM
error dialog box opens saying " please check- check SLC extension first"
But there is no error while opening SLC coverage graph in Check SLC extension button.

So, I download a geotiff file from usgs earth explorer (SRTM 1 Arc-Second Global) and put in dem/dem_tiff folder. Created a DEM_files.txt with name of tiff file in it in working path.
But when I click localhosted DEM button, it says DEM files have not been selected

I believe i have to create a xml file of tiff image so which option should I select from below metadata options

And what is about header files , how to create and put in working path.

[Tejaswi-06-24]

Actually I didn't downloaded all the toolbox required in matlab. And then re-downloading from the interface SLCs.
Also changing the required permission removed the error till " Visualize DEM" so far.
If anyone faces same issue above hopefully it helps.