Urgent Help with Excel Formula

Hi there,
I'm looking for help with this spreadsheet - we have a list of dates and are looking to find the maximum value / latest date fitting a criteria. I have tried using the MAXIFS and MAX(IF) formula, but it keeps returning lots of 01/01/1900 values, which seems wrong - would be great if you can help.
This is for an urgent project and we're looking for help from someone that can complete on same day - it is likely a few minutes work for someone who is experienced with Excel.
Look forward to hearing from you!
Vikesh
Column with Error: "Subs" Tab Column F
Column with Dates: "Orders" Tab Column C
Criteria: Last Order for Each Subscription ID on "Subs" Tab
Subscription ID can be found in column B on "Subs" Tab