Hi All,
Thought I'd share some found knowledge on an Expense Management feature in F&O. The feature is "Restrict expense report posting when project details are missing in project accounting distribution".
If you have this feature turned on then F&O will not allow you to post an expense report when set up for integration into Project Operations. This is because the accounting distribution for the expense report is set to post to the Expense integration account not the project in this scenario.
Hope this may save you some of the time I lost trying to figure it out!!