MapThat Scale Print – Type Error Lambda

by David Crowther

Question:

What is the cause of the ‘Type Error:<lambda>’ message?

Answer: 

The likely cause of the above MapThat Scale Print error message is an incorrect value in the DB_ID column for the MT_MAP_COLOURSETS table.

The value in this field allows MapThat to find the source basemapping if the selected source is spatial data e.g. OS Mastermap. The value defined will link to the DB_ID in the VE_DBCONNECTIONS table for your OS Mastermap database.

However, when referencing any external basemapping e.g. OpenStreetMap, you should leave this value as NULL.

If however by mistake you add a DB_ID value in for external basemaps - e.g. here we have added the DB_ID value of 40 to the OpenStreetMap basemap link – when you run the Scale Print job the <lambda> error message will be generated.

Instead, ensure that all your external basemapping layers have their DB_ID value set to NULL….

…. and your MapThat Scale Prints will now run and use those external Tile Services as your basemapping layers.