Miltiadis

In v14 go to step 5 export, export project. This will create an iwzip

If you run v17.1.2 pro and then select import and select the iwzip just created your project will be upgraded to v17 (without changing your existing v14 project).

There may be some "anomolies" caused by new features, but generally it will be a better website when you are finished. If on the other hand you wish to maintain your old v14 as an interim measure whilst you upgrade to the new functionality then you will be able to do so without issue.