This could be user error, but when I click on the red disc above my model and try to add supports, I see no change in the model. For example, after applying a microstructure filter, I select the recommended “light” (have also tried “solid”) support option, then click the “add” button on that dialog. I expect to see supports added, but the model is unchanged (or I am blind).
Yes we have noticed that something is not working correctly with the red dot in the last release. We will review it. In the meantime, if you want you can disable it going to File->Settings->Support Marks (red dot).
Solved in 2fd62ab7caa0c4e9157909ef007e2c9794cedcd5