Okay, what'd I do wrong

I have a classic license to SketchUp Pro (Mac version). My active maintenance and support contract expired in March. I took advantage of Trimble’s offer for a discounted 2 year subscription version. I paid for the subscription, got all squared away with my Trimble account and settings, and then downloaded the file. I transferred the file to my Applications folder as shown on the installation window. I got a message saying a 2021 SketchUp folder already existed and did I want to replace it. I hit “replace”.

I had icons for SketchUp and Layout on my dock so I closed those and removed them from my dock figuring that would clear the “tag” to my classic license versions. I opened my Applications folder and pulled SketchUp and Layout to my dock. I opened SketchUp, and since I assumed it was now the subscription version, it would not ask for a license key. It did not. However, when I go to SketchUp > Manage licensing it still shows my classic license and the subscription plan shows “subscription trial”.
So what am I missing?

I think you would have to sign in with your subscription credentials and license to activate, within the software. Right now it’s acting like you are in a trial. Try that out.

There is no special ‘subscription’ or ‘classic’ version of SketchUp, it’s the same installer and app. Only the way you activate it is different.
When you installed it, it didn’t replace the sketchup.lic file of your classic license, since they reside in the user library that doesn’t get overwritten as the folder in the Application folder.

If you want to save activations of your classic license for later use or on another machine, you would have to remove the classic license in the Welcome screen > License > Classic License tab
Hit remove and it will increase the amount of activations that you could use later on.

My guess is that your subscription seat hasn’t been assigned to the email address or Trimble ID that you use when signing in to SketchUp.
When you have a subscription tied to an email address, you can actually change the enduser and assign the seat to another email address.

Goto myaccount.trimble.com and log in with the email that bought the subscription, goto the Member area and check if the seat is actually assigned to a Member or email address.
Once you are sure the seat is taken, log out in SketchUp and sign back in to trigger the changes made.

Yup, that did it. I think I’m back in business now, thanks.