VERIFIED SOLUTION i

How to import an OS MasterMap file in .gmz format

Products affected: MapInfo Pro™
 
*.gmz format is a compressed version of a *.gml file.
To open in MapInfo Pro, decompress the file and then rename it using the following steps:
  1. Un-compress the *.gmz file using a suitable utility such as WinZip, WinRar, 7zip, etc
  2. In the uncompressed folder there will be a file that will have no file extension -  rename the file so it has a ..gml extension
  3. Once file is renamed with .gml extension, launch MapInfo Pro and go to Table > Import and  choose file of type: OS MasterMap (*.gml)
UPDATED:  September 19, 2017