There are three common scenarios for not being able to open a file in commenting mode:
1.) You are not able to install software or you are on a non-Windows machine so the Commenting tool available
2.) The commenting window appears but the upper window is blank
3.) The Enhanced Web will not load the commenting tool
Troubleshooting scenario #1:
The commenting tool requires that it be installed on a Microsoft .NET environment. It will not run on a MAC and cannot be used if the you cannot install software.
Troubleshooting scenario #2:
The Primary cause for this is usually another installed program is preventing Office from loading the document or there is an error with the Microsoft Office file associations.
start by checking the file associations. (if you need help checking the file associations reach out to your authorized support contact and have them look at the following technote "Configuring Office File Associations"
If any of the .doc, .docx, .xls, .xlsx, .ppt or .pptx file associations are not set to open with Microsoft Office the commenting tool will not load the document correctly.
In particular there is an application that is bundled on all new Dell systems called “Dell Protected Workspaces,” that is known to takes possession of Microsoft Office file associations.
If this program is installed it will need to be uninstalled and the user will need to run the repair tool on office to completely rebuild the file associations.
Second check to see if either the “Microsoft Office Compatibility Pack” and “Nuance PDF Converter” are installed on the computer. These applications are known to prevent the commenting tool from loading the document. If one of the programs is installed, it will attempt to jump in front of Microsoft Office when the commenting tool is loading, often popping up a hidden dialog. The solution is to uninstall the conflicting software and ensure that the associations for Office 2007 and 2010 are set up properly.
Troubleshooting scenario #3
For Internet Explorer 10 and 11 check to see if the browser is in compatibility mode. If it is not in compatibility mode the Web Browser will not be able to load the commenting tool.
Note:
if you need help checking the file associations reach out to your authorized support contact and have them look at the following technote "Configuring Office File Associations"
if you need help changing your compatibility setting please refer to the following FAQ item "How do I change my compatibility mode settings for IE 9, 10 and 11?"