Font exception not showing up when should have?

We have several operators working on Coreldraw X7.  One of our operators opened artwork  which should have produced a font exception but didnt, resulting in us producing artwork with the incorrect font. All of our other operators on trying to open the same job got the font exception message as expected. Any ideas why one operator wouldnt get the font exception message? 

Everyone working on the same version of Coreldraw. 

The font was  Trajan Pro-Bold(Type1) (Western)   Suggested Substitute was Trajan Pro- Bold (OpenType - PostScript) (Western)