I am still having problems with this...... I finally had both programs running smoothly for a year or two then started seeing crash problems following Yosemite upgrade then El Capitan computer crash's where every single invoice. Upgraded both E.I. and inventory. Now E.I. will not update quantities in inventory once an invoice is created, it updates the stock in E.I. but no communication with inventory.
communication is working between inventory and E.I. because I can go to E.I. / preferences / inventory / update now and that works just doesn't update back to inventory
Mac version 10.11.3
Inventoria 3.66
Express Invoice 4.45