rebuild index exception

[friuns2]

when i click rebuild index i get this error
unity3d 2018.3.12f

ArgumentException: parsing "\s+[%#&_]+\w$" - Unrecognized escape sequence _.
System.Text.RegularExpressions.RegexParser.ScanCharEscape () (at <3845a180c26b4889bc2d47593a665814>:0)
System.Text.RegularExpressions.RegexParser.ScanCharClass (System.Boolean caseInsensitive, System.Boolean scanOnly) (at <3845a180c26b4889bc2d47593a665814>:0)
System.Text.RegularExpressions.RegexParser.CountCaptures () (at <3845a180c26b4889bc2d47593a665814>:0)
System.Text.RegularExpressions.RegexParser.Parse (System.String re, System.Text.RegularExpressions.RegexOptions op) (at <3845a180c26b4889bc2d47593a665814>:0)
System.Text.RegularExpressions.Regex..ctor (System.String pattern, System.Text.RegularExpressions.RegexOptions options, System.TimeSpan matchTimeout, System.Boolean useCache) (at <3845a180c26b4889bc2d47593a665814>:0)
System.Text.RegularExpressions.Regex..ctor (System.String pattern, System.Text.RegularExpressions.RegexOptions options) (at <3845a180c26b4889bc2d47593a665814>:0)
Haste.HasteMenuItemSource..cctor () (at Assets/Haste/Editor/Sources/HasteMenuItemSource.cs:15)
Rethrow as TypeInitializationException: The type initializer for 'Haste.HasteMenuItemSource' threw an exception.
Haste.Haste+<>c.<.cctor>b__33_2 () (at Assets/Haste/Editor/Haste.cs:96)
Haste.HasteWatcher+d__28.MoveNext () (at Assets/Haste/Editor/HasteWatcher.cs:116)
Haste.HasteSchedulerNode.Next () (at Assets/Haste/Editor/HasteScheduler.cs:45)
Haste.HasteScheduler.Tick () (at Assets/Haste/Editor/HasteScheduler.cs:116)
Haste.Haste.Update () (at Assets/Haste/Editor/Haste.cs:262)
UnityEditor.EditorApplication.Internal_CallUpdateFunctions () (at C:/buildslave/unity/build/Editor/Mono/EditorApplication.cs:200)

[jimfleming]

Weird. Seems C# doesn't like my RegEx anymore. That code is on this line: Assets/Haste/Editor/Sources/HasteMenuItemSource.cs#L15

I think removing the backslash before the underscore should fix it.

[friuns2]

yes it fixed it