This section describes how to resolve common problems experienced when publishing maps with Mappin.

LOAD LAYERS doesn’t show anything

You’ve uploaded a QGIS project and when you click LOAD LAYERS to get a list of layers to publish from your project, you get an empty list.

This issue is usually caused by QGIS Server complaining about something in the uploaded project. The most common issue is a layer which it cannot find the data for. Check the following:

  1. Does the QGIS project reference only layers that are in the Mappin database or are otherwise internet accessible?
  2. Does the project load-up OK in QGIS desktop if you move the .qgs file to a different location on your computer?
  3. Does the project have layer groups sitting within layer groups? This is not supported.

The ZoomStack background maps provided look grainy / pixelated

The ZoomStack maps provided as background maps for UK Mappin customers are provided by a WMTS server with a gridset using the following resolutions:

  • OSBackgroundMaps: 2000,1000,500,200,100,50,25,12.5,5,2.5,2,1,0.5,0.25
  • OSZoomStack: 2048,1024,512,256,128,64,32,16,8,4,2,1,0.5,0.25,0.125,0.0625,0.03125

For the maps to look crisp and clean, your Resolutions setting (in the Map configuration in Mappin’s admin interface) should be set to the same.