Attachments do not show up

This time I deleted something in the database to get rid of my rogue page (see previous threads). Since then the attachments made with the form {attach:file.ext} do not work. Instead of making the link it just shows the name of the file. I get this error message in the logs: 23:15:57,855 INFO [Engine] StandardContext[/xwiki] Velocity [error] RHS of #set statement is null. Context will not be modified. [line 6, column 1] Where should I look to get the attachment back at work? Do you know? Thanks. Marc