Most probably, the folder of this module under the "modules"directory on your FTP is missing some .php or .html files.
In order to eliminate this,
1)Find out, how the module is called;
2)Open the original folder of the module located in the "sources" folder of your template package.
3)Open the same folder of the module on your FTP and compare the files in the two folders.
4)Move the missing .xml or .php files from the original module folder to the one on your FTP.
5) Try adding a new module from your admin side to check if the problem is still there.
Another way around is to re-install the module, but note that by deleting it from the admin side, you will delete the former module settings or even the module itself from the "Module Manager" aswell, so the manual method is more preferable.
Also, please check the demo below for some more information.