User has a phased invoice showing percent complete as 105% for one of the phases. This phase has some expense entries associated with it.
This happens when you have kept expenses as part of the contract amount for the phase, but no contract amount is assigned to the expense part. So you need to assign a contract amount to the expenses. You can do that by opening the project phase details on the Projects > General > Details screen and clicking Split Amount. Then you can specify the contract amount for expenses in the Contract Expense Amount field.