Update : As of 7th March 2018, this is all resolved.
As of 6th March 2018, if you try to fetch a new copy or submit a new data feed to Google Merchant, you will see an error saying File pre processing:failure.
This is only a visual message, all products if correctly submitted (meaning no errors), will be processed and submitted. You can check the updates after 2 to 3 hours. You will notice all new products are added and all existing products are updated.
What Should I Do?
With all issues, first always submit feedback. By going to Google Merchant > Top Right Corner > Feedback