Symptom:
It shows a big "H" icon instead of Design Thumbnail for the design files in the large icon view in "My Designs".
Solution:
It is Hatch software installation related issue. A design thumbnail management file is not registered by Windows operating system properly. Please download and run a software utility from the link below to fix this issue:
1) Download the file on your PC
2) Unzip the downloaded file to a folder
3) Get into the folder and double clicking on the "RegisterEMBShellExt.exe" file
Note: After it runs, the Design Thumbnails should be displayed normally.