This can occur when a mistake was made when the table was created.
pdm_extract wsptbl > tbl.dat
- Open the file in a Text Editor and Delete all rows except for the column headings and the table / row in question (everything EXCEPT for zxxxxx).
pdm_load -r -f tbl.dat
- Navigate to your site\mods and site\mods\magic directory and find the altercol and altertbl.
- Remove the reference to zxxxxx.