DX10 Fixer v3 is avaiable on FSS store....I just downloaded it there.
You can only download it if you are an existing customer on FSS store and you have already purchased DX10fixer there.
If this is the case, then go to FSS store homepage, choose my account button and check your download files. You will find the download zip-file there.
FSS store soled the DX10 fixer for Steve for some time. But meanwhile Steve sells the tool exclusively on his own webpage.
FSS store doesn't sell it anymore to customers. You can only get update files as an existing customer if you purchased the DX10 fixer in the past.
If you didn't purchase it already, then look on the following website. You have to buy it directly from Steve's webpage
https://stevesfsxanalysis.wordpress.com/2014/12/30/dx10-scenery-fixer-will-be-temporarily-unavailable/