Can I change content on multiple submissions at once (mass changes).

Can I change content on multiple submissions at once (mass changes). For example Multiple teams have now progressed up an age group - so they are now U14 and not U13 - I want to do a mass change on multiple data submission at same time.

Unfortunately, that is not possible. You can edit submissions one by one only. Open a new thread if you need anything else, we will be glad to assist you.