Error: The document date cannot be before the period lock date
Another error message with the same cause and solution looks like this:
The cause:
This error comes up when an expense (or expenses) has a presentment date that falls within a locked period. This can happen when:
The Pleo expense was not exported in time (i.e., before the books were closed for the respective timeframe).
There is a discrepancy between the UTC timestamp of presentments versus the date of the purchase in your timezone. For example, a presentment from May 31st at 23:30 should go into the May books in Xero. However, Pleo will have stamped it as June 1st.
The solution:
Log into Xero and open the books for the specific date range (under Accounting - Advanced - Financial settings).