Sketchup says I'm not allowed to open new file, but I have just paid an annual subscription

You are not Licened.
You can continue to use sketchup, but you will not be allowed to start e new file or open an existing file.

This is what it says. But when I look in Trimble it says I have an active account. >

STATUS

Active

RENEWAL DATE

29 - APR - 2021

What can I do about this problem?

I got an email 12 days ago to update my creditcard info which i didnt because I already paid. Is it really this I have to do even though I already paid a full year just 3 weeks ago?

I see your payment as having gone through too. If the card expires after the date you renewed, you have about 11 months to remember to update the card. Or leave it alone, and look out for failed to process emails next time you are due to renew.