Invalid acc tree in IE11 on Windows 8.1 x64

Hello
I found "Invalid acc tree in IE11 on Windows 8.1 x64"

issues are
1) HTML contents are not found by AccExplorer32.exe
2) HTML contents are not found by Inspect.exe
3) HTML contents are not read by NVDA screen reader

above issues are exist in IE11 32bit mode on Windows 8.1 x64
but on IE11 64bit mode on Windows 8.1 x64, all above issues are not exist.

thank you for advance.