Upload Documents and Check In option is greyed out or Unavailable.
The option is greyed out:
Please check the browser using, it does not support under Chrome, Firefox, only works in IE. This is a limitation of SharePoint.
The option is not available:
- Please make sure the product is deployed under the current web application, and the feature is activated in site collection.
- Please check if Microsoft Office is installed in the local machine.
Applies for: SharePoint 2013, SharePoint 2010, SharePoint 2007