Thank you for your post into the forum and sorry that you have encountered this problem.
To resolve this issue, please download the snippets folder using this LINK.
Extract out the snippets folder contained within the downloaded zip file.
Next locate the existing snippets folder normally located in this directory:
C:\\Users\\<user_name>\\AppData\\Local\\Red Gate\\SQL Prompt 5
Rename the existing folder. Next copy & paste in the downloaded snippets folder. Open SSMS and the snippets should now appear.