It all started when sudenly one of my assets (Behavior Designer) couldn’t detect new tasks. I tried restarting the project then this happened.
I’m running Unity 2019.2.15f1 on Windows 10 using NET Framework 4.X (Also tried with NET 2.x)
In the past, i’ve been using Unity without any trouble when i had Windows 7 and NET Framework 3.5. I activated NET 3.5 on Windows 10, but project settings doesn’t recognize it.
Same thing happened to me last Friday morning when Unity Hub made me do an update. After multiple uninstalls/reinstalls and a handful of different versions I get the same thing when a new project is created and any type of script is either added or created. I’ve been able to roll back to 2017 which doesn’t require Unity Hub and it runs fine but I sure would like to return to a new version of Unity
Just a heads up, I did a complete uninstall of Unity, Unity Hub, and then wiped out the Unity and Unity Hub folders in the C:\Program Files directory as well as those in the users AppData\Roaming directory. Did another restart just in case. I then followed this thread to get an older version of Unity HUB https://discussions.unity.com/t/767592
So far I was able to get a 2018 Unity version installed (Haven’t tried 2019) with this and was able to open a new project without the errors. It sounds like Unity Hub updates on its own though so I am not sure how long I can go without it auto updating itself and starting me back with the initial error. Unfortunately it looks like Unity devs wont even acknowledge a problem with their latest Unity Hub update yet so not sure how long things can be fixed and get everything back to normal