To reproduce:
1. Open users attached project "New Unity Project.zip"
2. Open Preferences window

Expected result: Preferences window is opened
Actual result: getting this in the console:

ArgumentException: Illegal characters in path.
System.IO.Path.GetFileName (System.String path) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
UnityEditor.SettingsProvider..ctor (System.String path, UnityEditor.SettingsScope scopes, System.Collections.Generic.IEnumerable`1[T] keywords) (at C:/buildslave/unity/build/Editor/Mono/Settings/SettingsProvider.cs:76)
UnityEditor.SettingsService.<FetchDeprecatedPreferenceItems>m__1 (UnityEditor.AttributeHelper+MethodWithAttribute method) (at C:/buildslave/unity/build/Editor/Mono/Settings/SettingsService.cs:58)
System.Linq.Enumerable+SelectListIterator`2[TSource,TResult].MoveNext () (at <1b13ba6391c74847bbc3eddc86df7eee>:0)
System.Linq.Enumerable+ConcatIterator`1[TSource].MoveNext () (at <1b13ba6391c74847bbc3eddc86df7eee>:0)
System.Linq.Enumerable+WhereEnumerableIterator`1[TSource].ToArray () (at <1b13ba6391c74847bbc3eddc86df7eee>:0)
System.Linq.Enumerable.ToArray[TSource] (System.Collections.Generic.IEnumerable`1[T] source) (at <1b13ba6391c74847bbc3eddc86df7eee>:0)
UnityEditor.SettingsService.FetchSettingsProviders () (at C:/buildslave/unity/build/Editor/Mono/Settings/SettingsService.cs:41)
UnityEditor.SettingsWindow.Init () (at C:/buildslave/unity/build/Editor/Mono/Settings/SettingsWindow.cs:167)
UnityEditor.SettingsWindow.OnEnable () (at C:/buildslave/unity/build/Editor/Mono/Settings/SettingsWindow.cs:99)
UnityEditor.SettingsService:OpenUserPreferenceWindow()

Reproduced on:
2018.3.0a4 2018.3.0b1 2018.3.0b10 2019.1.0a10

Not reproduced on:
2018.2.17f1 2018.3.0a3

Notes:
Reproduced on a Win10 machine
Doesn't reproduce on MacOS 10.14 machine