Hello Lisa,
Do you receive any error message when you try to insert row?
What is the default browser in use?
Do you find the same issue if you use a different browser?
If Internet explorer, you may reset IE settings using the link below and check if you are able to download the app.
http://support.microsoft.com/kb/923737
Disclaimer: The Reset Internet Explorer
Settings feature might reset security settings or privacy settings that you added to the list of Trusted Sites. The Reset Internet Explorer Settings feature might also reset parental control settings. We recommend that you note these sites before you use the
Reset Internet Explorer Settings feature.
I hope the above information helps. Let us know if you need further assistance.
Thank you.