There are few factors that you need to check in your machine if the “Automation tool” is greyed out .
“Automation tool” is greyed out by-default & re-installing the software is not going to solve this problem.
To enable it you need to install the plugin of your printer/scanner that you are using in your machine .
You can get that plugin from the tech support of your printer/scanner not from Adobe tech support as they do not deal with any 3rd party plugins . Neither they provide or develop one .
Once the plugin is installed,make sure you are using “Expert” mode because in Quick & Guided mode you will not be able to use it .
Examples of plugins : Goggle Nik Collection , ON1 Effects 10 , Merge to HDR EFEX PRO etc
Location of plugin folder is as follows for (Windows)
C:\Users\(User_Accout_Name\AppData\Roaming\Adobe\Photoshop Elements\(Version of Photoshop Elements)\Plugins
The Elements Therapy 