I have an issue that crops up now and then and across several computers that I have been testing Express Invoice on.
The Issue: When creating a new invoice I go through all the usual like adding items to the invoice from the item list then click either Record and Preview or Record and Email. The invoice pops up on screen but is blank with with no items showing. in the date field of the invoice it shows INVALID DATE in caps.
Further playing around in my attempt to try find out what makes this happen I see that if I disconnect from Dropbox it never happens. After a creating an invoice that failed with the error shown above if I simply recreate the invoice again it always works the 2nd time around.
I get this same issue on the following:
iMac (BigSur) Macbook Pro (BigSur) Macbook (Catalina). Its occurring on my office network, my home network and also on a 4g test network.