I have this appearing on loading my project: Compiler redirection error: System.ArgumentOutOfRangeException Length cannot be less than zero. Parameter name: length at System.String.Substring (System.Int32 startIndex, System.Int32 length) [0x00053] in <a90417619fac49d5924050304d0280bb>:0 at Program.GetUnityEditorDataDir () [0x00028] in <e78adca0e712493f9396b48e2b41f2ca>:0 at Program.Compile (System.String args, Logger logger) [0x0002f] in <e78adca0e712493f9396b48e2b41f2ca>:0 at Program.Main (System.String args) [0x0000d] in <e78adca0e712493f9396b48e2b41f2ca>:0 WARNING: The runtime version supported by this application is unavailable. Using default runtime: v4.0.30319 Anytime I try and do something it is constantly compiling scripts and downloading from cache server and basicaly freezes up and I have to close and restart to see what is happening... also have 999+ warnings talking about something didn't update because it's not in the assets folder... What is going on?? How can I remove this and go back to the last release? This is ridiculuos. Updating should not render a project unusable...where is the backwards compatibility?