There's a bunch of themes ready to update, for example:
[License free update available] You have version 2.1.1 installed. Update to 2.1.5. Requires SP Version 6.2.0.
But, when I try to update them I get a forbidden access error message
And, for example, if I go to https://simple-press.com/uploads/downloads/simple-press/themes/default-2.0.0/default.zip&wpupdate=1
Thanks for reaching out. You are correct, yesterday we made some changes to the backend and how the free theme downloads are handled. We just released version 6.10.1 that addresses this issue. Please update to the latest version of Simple:Press and try again and it should work as expected.
Joakim @ Simple:Press