When you enable the developer tab and want to use the new Content Control from Microsoft Word 2010 onward then you might receive a message “The command is currently disabled. This document has been opened in Compatibility Mode. To use this feature, convert your document to a new file format by clicking the File tab and then clicking Convert”
Do the follow:
1. Click the File tab.
2. Select Options.
3. Choose Save inside the options.
4. Select *.docx in Save files in this format:.