When the cloud download icon is green but a catalog download is not working properly, click on the green cloud icon and click the trash icon (Delete) to delete the pending catalogs visible in the window.
Next, close DomuS3D and clear the cache by opening the IMPORT folder of the program (...\DomuS3D\import) and delete all files in the folder with the name "xadb...".
Lastly, go to the folder DomuS3D\TEMP and delete the file "dbstat".
This article is valid for the 2017 version and later,