Mp4 muxer does not generate proper video into folder named with "ŽŠČ" and similar

Hi all, 

I discovered a bug, neither AE nor Media encoder generated promer mp4 file. It is some muxer problem, because audio and video parts seems to be OK, but the result is only 24bytes mp4 with no data inside. 
And I also discovered the reason..

It is only in case, when some national specify characters in filename structure are present. 

example: Folder "Živý kraj" is not acceptable for Encoder or AE. After renaming folder to "Zivy kraj" is export OK.
It worked with all characters in older AE version..