I had this and I found the answer in a Q&A for another product. Went to My Products, Studio One is shown. There is a small arrow to the right of that listing (on Safari anyway). I clicked it - it is a "refresh". After the twisty finished, I went through the steps to click Download and it worked. I haven't gone home to install it yet, but I am optimistic.
UPDATE: no go. Now I get the "license isn't issued to this computer". Opened ticket with Presonus.
While waiting for a response I tried removing the activation, re-adding, and download the license but now I am back to Access denied, and the refresh doesn't help.