I try to intall Qt5 from here:
It makes MM fail during installation, so we can mark it in tested apps list as FAIL.
Possible the bug can be related to CORE-10611, but I'm not sure.
UPD: I retest this intaller from NTFS disk. It install successfully! Also I have noticed that reading a big files from FAT partition cause a some memory leaks (you can see it on task manager screenshort). So, I can guess that we have some memory problems in fast_fat driver.