Now Will Not Read Txt Files

[LeePa]

Hello Mi-Folks:
I have the Mi-Note.
An update came to my phone a couple of weeks ago.
Now the phone will not read text files from my USB.
There is no problem with video files, no problem with audio files.
I thought it was a cable / adaptor problem ... no it is not
I tried several different readers: MOON+ READER... WPS OFFICE... HTML VIEWER... TEXT VIEWER
None of these will read my USB Thumb-Drive text files.

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MIUI VERSION = MIUI 7.2.4.0(MXECNDB) I stable
Kernel version = 3.4.0-g0c665cd-00550-g1352de7

Does anybody have any suggestions?? Recommendations??
Is there any explanation WHY this happened??
Help Please...
--LeePa