Unable to generate preview

Unable to generate preview

Dear all,

I have got this document that i have uploaded to the system and i want it to work with merge. However, whenever i select a couple of contacts, i click on the document and try to merge. When i choose Mailings, Finish and Merge and then preview document, it says Unable to generate preview.

Can anyone help me with this? How can i get around this?

Warm Regards