The MasterCook.com web importer has always saved the recipe to an online cookbook. That will never change. We have many customers who do not even have a Windows computer. It would not work for them if we did it any other way. This article was created 6 years ago and explains how the web importer has always worked: https://support.mastercook.com/hc/en-us/articles/216890146-Using-the-MasterCook-com-Web-Importer
There was a Download button in the web import window that appeared after the recipe saved to your online cookbook. That Download button was only for version 14 users like it said. Version 14 is no longer supported. That Download button corrupts cookbooks in MasterCook 15 and MasterCook 20 and confuses our customers, so we removed it.
You are supposed to sync your cookbooks with MasterCook 15 and MasterCook 20. Please read this article: https://support.mastercook.com/hc/en-us/articles/216898726-MasterCook-Synchronization
If you were using the MasterCook 14 Download button, your cookbooks will not sync properly. You will need to clear your account and start anew with syncing as explained here: https://support.mastercook.com/hc/en-us/articles/115000151746-Clear-Recipes-from-MasterCook-com