1. Error "The field value is not a date. Expected format: MM/DD/YY" (US Invoices). 

2. Captured values are perceived as text, not a date (some separators or spaces can be removed).

Solution

1. Invoice Date field properties>>Data

Data Type: Date>>Edit

Enable: 

-May include month in words

-order of date components: Day-Month-year AND Month-Day-Year

-order of date components: Use first acceptable date format