1) Make sure you are on the "clients" tab (the one showing the list of all your client), not actually in the file itself.

If that doesn't work....

2) Update your 2017 software (using WebSetUp & force it to reinstall if necessary) - You must have the last update from late in the year (ie, Nov/Dec of 2018) as that's the one that has the proforma/organizer function.