I recently upgraded our test system from 220.127.116.11 to 7.6.1. I was testing Opportunities and Revenue Line Items and I can't save an Opportunity. We have been using Revenue Line Items when we rolled out 7.x and I didn't make any configuration changes to Opportunities in the Admin panel - we want to continue using Revenue Line Items. When I enter an opportunity and click 'Save' or 'Save and View' nothing happens except the Save button toggling back and forth to which save option I select. I went as far as to see if my required fields were a problem and tried to save an empty opportunity, but I am not even getting an error on missing required items. Then I notice in the Revenue Line Items subpanel a list of fields we don't use, almost like out of the box fields. When I check Studio to be sure the upgrade didn't change my layouts, all of the record, list and subpanel layouts look right. Although I clicked Save, my new opportunity isn't in the list view.
Also clicking Cancel will not take me out of the opportunity back to the list view. It doesn't do anything until I click on the Opportunities module and asks if I want to disgard my changes.
Viewing an existing Opportunity has the correct Revenue Line Item subpanel. But adding a Revenue Line Item will not save either.