Insert Word document

I have an Excel workbook into which I have inserted several Word documents as text objects, shown as icons in the worksheets. This has worked well for about a year. However, in the last few days something has changed.  Excel seems to think that the documents are pictures.  If I click on the icons, the picture toolbar appears and I can't find any way of retrieving the documents.  If I insert a new document now, it appears to work correctly.

Any suggestions please?