The Cat Scan Editor examines all the content in your document and checks the corresponding Proofing Languages. The proofing language is the language that Word uses to check the spelling and grammar of the corresponding content. This highlights spelling errors, and is required to be Set to English.

The Cat Scan Editor accepts;

English Codes

en-GBEnglish (United Kingdom)
en-USEnglish (United States)
en-AUEnglish (Australia)
en-nzEnglish (New Zealand)

Any content in the document which is set to any other proofing language will flag an error. To fix this error you need to select all the content in your document and set the proofing language to English.

Setting Proofing Language

To fix any error reported from the Cat Scan Editor, you need to firstly Select All your document content using shortcut Ctrl + a.

In the Review within the Language section of the ribbon Select Language -> Set Proofing Language...

In the dialogue, select one of the versions of English which is listed in the table above and then Click OK.

All your document content Proofing Language should now be set you English, retest your document.