The software is changing all the time and it might be why you have problems now but just to be clear you can print a part without support and it will be ok, correct ?
Keep us updated and we can help you out 
Next step lets work on this model for testing and start changing your settings look in your preview screen so you can see what is changing. This is just some basic settings to get you going on setting up your tree supports correctly.
Good tree support setting no overhangs.
Bad Tree Support setting big overhangs.
Weak tree supports depending on what filament you are using if you select support base default or if you turn on the prime tower this will go away.
Bad Day Support Model
Support Test
I recommend you download the Orca slicer. It has more settings for support. This is what I’m using in the photos.
Go to the bottom of the page and pick your OS.