Failed to run script updater.

Questions & Answers
1

Kinda frustrating. Can anyone help with this??

Failed to run script updater.
Please, report a bug to Unity with these details

System.IndexOutOfRangeException: Array index is out of range.
  at BooUpdater.BooDocument.FindPrevious (Boo.Lang.Compiler.Ast.LexicalInfo start, Char c) [0x00000] in <filename unknown>:0 
  at UnityScriptUpdater.FixParsedSourceLocations.OnMethodInvocationExpression (Boo.Lang.Compiler.Ast.MethodInvocationExpression node) [0x00000] in <filename unknown>:0 
  at Boo.Lang.Compiler.Ast.MethodInvocationExpression.Accept (IAstVisitor visitor) [0x00000] in <filename unknown>:0 
  at Boo.Lang.Compiler.Ast.FastDepthFirstVisitor.OnExpressionStatement (Boo.Lang.Compiler.Ast.ExpressionStatement node) [0x00000] in <filename unknown>:0 
  at UnityScriptUpdater.FixParsedSourceLocations.OnExpressionStatement (Boo.Lang.Compiler.Ast.ExpressionStatement node) [0x00000] in <filename unknown>:0 
  at Boo.Lang.Compiler.Ast.ExpressionStatement.Accept (IAstVisitor visitor) [0x00000] in <filename unknown>:0 
  at Boo.Lang.Compiler.Ast.FastDepthFirstVisitor.OnBlock (Boo.Lang.Compiler.Ast.Block node) [0x00000] in <filename unknown>:0 
  at Boo.Lang.Compiler.Ast.Block.Accept (IAstVisitor visitor) [0x00000] in <filename unknown>:0 
  at Boo.Lang.Compiler.Ast.FastDepthFirstVisitor.OnConstructor (Boo.Lang.Compiler.Ast.Constructor node) [0x00000] in <filename unknown>:0 
  at Boo.Lang.Compiler.Ast.Constructor.Accept (IAstVisitor visitor) [0x00000] in <filename unknown>:0 
  at Boo.Lang.Compiler.Ast.FastDepthFirstVisitor.OnClassDefinition (Boo.Lang.Compiler.Ast.ClassDefinition node) [0x00000] in <filename unknown>:0 
  at Boo.Lang.Compiler.Ast.ClassDefinition.Accept (IAstVisitor visitor) [0x00000] in <filename unknown>:0 
  at Boo.Lang.Compiler.Ast.FastDepthFirstVisitor.OnModule (Boo.Lang.Compiler.Ast.Module node) [0x00000] in <filename unknown>:0 
  at Boo.Lang.Compiler.Ast.Module.Accept (IAstVisitor visitor) [0x00000] in <filename unknown>:0 
  at Boo.Lang.Compiler.Ast.FastDepthFirstVisitor.OnCompileUnit (Boo.Lang.Compiler.Ast.CompileUnit node) [0x00000] in <filename unknown>:0 
  at Boo.Lang.Compiler.Ast.CompileUnit.Accept (IAstVisitor visitor) [0x00000] in <filename unknown>:0 
  at BooUpdater.BooUpdater.FixParsedSourceLocations (IEnumerable`1 inputs, IAPIUpdaterListener listener, Boo.Lang.Compiler.CompilerContext result) [0x00000] in <filename unknown>:0 
  at BooUpdater.BooUpdater.CompileScripts (IEnumerable`1 inputs, IEnumerable`1 defines, IEnumerable`1 references) [0x00000] in <filename unknown>:0 
  at BooUpdater.BooUpdater.RunUpdater (APIUpdater.Framework.Core.SourceFile[] inputs, IEnumerable`1 defines, IEnumerable`1 references) [0x00000] in <filename unknown>:0 
  at APIUpdater.Framework.Core.APIUpdaterBase.Update (APIUpdater.Framework.Core.SourceFile[] inputs, IEnumerable`1 defines, IEnumerable`1 references) [0x00000] in <filename unknown>:0 
  at ScriptUpdater.Program.UpdateLanguage (IScriptUpdater updater, APIUpdater.Framework.Configuration.CompilerResponseFile responseFile, System.String unityDataPath, System.String outputPath) [0x00000] in <filename unknown>:0 
  at ScriptUpdater.Program.Main (System.String[] args) [0x00000] in <filename unknown>:0

UnityEditor.Scripting.Compilers.ScriptCompilerBase:BeginCompiling()

2

Actually, I fixed this issue.

To fix this, all you really need to do is try and see if there are any errors with any other scripts. If there is, delete them. Or, you rewrite a certain script. These are the solutions I did.