Check the Remaining Total. If the Total is not zero then a Distribution is wrong, or missing, or entered twice. It is also possible the Invoice cost in the Invoice Header is incorrect. You will need to correct things until the Remaining Total is zero. If the Invoices are not completed the Daily Activities cannot be completed
Check the number of Distributions if your Remaining Total is not zero. It is a quick way to see if you missed something or added something more than once.