This is the first time I've experienced it and note my eFile date is still 04/15. Not sure if IRS will now impose a penalty/fee etc. Anyone know? Seems a software issue but its too late now for us to Print the documents and Mail the Check through a After Hours Post Office!!

This is a known issue, they are working on currently.

In the meantime, if you need to pay your federal taxes due you can go to the IRS website directly.  You will just need to select pay by check for your filing method. You will get a voucher in your return, but do not pay the voucher if you are using the IRS website. 

 https://directpay.irs.gov/directpay/payment?execution=e1s1

https://ttlc.intuit.com/replies/7419959

(Edited 4/15/19 @ 10:45PM EST)