@taming: That was the wrong type for the location column. The four columns needed are
- Current Reading Location: This is used to store the link to the current location in the book. It must be a "Text, column shown in the tag browser". It is recommended that the column is not shown in the column list and hidden in the tag browser.
- Percent Read: This is the current percentage read for the book. It must be an "Integers" column.
- Rating: This is the rating of the book. The standard "Rating" column in calibre can be used, or a custom used. If a custom column is used, it must be either a "Ratings, shown with stars" or an "Integers" type column.
- Last Read Timestamp: This is the date the book was last read. This must be a "Timestamp" type column.
So, the column for the location has to be "Text, column shown in the tag browser". Any other won't work. And the configuration dialog will only display columns that are the right type for the usage.