Compile error for mapped partial class when the number of files is greater than eight on UWP

IDE: VS 2015
Version: 8.4.96.2041
Target (If relevant): UWP
Description:

UWPApp1.zip (60.6 KB)

  1. These are my test files in the same “test” folder:

And 1.cs ~ 7.cs are all empty files.

  1. MyTask.cs

    public partial class MyTask {
    }

  2. MyTask_ECHOES.cs

    /*
    Compile error: (E57) The type visibility for “UWPApp1.test.MyTask” does not match other class parts
    1) 1.cs ~ 7.cs are all empty files
    2) Just try to delete 7.cs to reduce the number of files in “test” folder to 8,
    this compile error will be gone, and everything works like a charm.
    */
    public __mapped partial class MyTask => System.Threading.Tasks.Task {}

This issue seems be forgotten?

Thanks, logged as bugs://76303

bugs://E18401 was closed as fixed.