If you use Raster Design to merge images imported with Plex.Earth, it will show up an error message stating it's not possible due to different scales in axes X & Y . This is because Plex.Earth applies different scales in order to improve accuracy in geo-reference.

The issue can be by-passed and you will be able to merge them with Raster Design, by following the steps below:

1. Export the world files of the mosaic images through Raster Design or simply use the option of Plex.Earth to automatically export world files when creating mosaics (see Settings -> General tab)
2. Delete and detach all the mosaic images from the drawing.
3. Import the images again into AutoCAD, one by one, using Raster Design (select to use the world files). When prompted to edit scales, please confirm.

Please be aware that there are some drawbacks:

• You will have to re-import images one-by-one due to a limitation in the functionality of Raster Design, which will not prompt you to equalize the scales when importing many images at once.
• Geo-reference is slightly modified, because Raster Design is changing the scales.