Good to know ^^, I only mentioned it just in case.
Anyway, this is the logs I got from the error:
"#### MiX-B1707251_2017-08-01_17-08.txt ************************
MiXplorer v6.16.7-B1707251
Device: Acer B1-770, Brand:Acer
API level: 21
CPU ABI: armeabi-v7a, armeabi
------------------------------------
D/Storage> Refresh storages.
D/ActivityResult> Request:111, Result:0
I/MiX> MiX resumed.
I/MiX> Available storage: MAIN_SD /storage/emulated/0
I/MiX> Available storage: EXT_SD /storage/sdcard1
I/MiX> Available storage: SYSTEM /
I/MiX> ----- Operation started ----------------------
I/MiX> Action: DELETE
I/MiX> Calculating...
I/MiX> Total: 1
I/OperationHelper> Delete /storage/emulated/0/Download/It my birthday, Have some ߎ¢irthday progressߎ®mp4
E/CategoryHelper> dbID java.lang.NullPointerException
I/CategoryHelper> Uri null from > /storage/emulated/0/Download/It my birthday, Have some ߎ¢irthday progressߎ®mp4
I/MiX> One file deleted
0s
I/MiX> ----- Operation finished. 0s -------------
D/TOAST> One file deleted
0s
I/MiX> MiX paused.
I/DB> Refresh DB...
D/ActivityResult> Request:111, Result:0
I/MiX> MiX resumed.
D/HUB> ITEM >> /storage/emulated/0/Download
"
For example, I download this video:
http://thumbtackdev.tumblr.com/post/151626537358/it-my-birthday-have-some-birthday-progress
And this is how it looks:
https://ibb.co/fiEAPk
https://ibb.co/k28Rx5 ("deleted" but then...)
https://ibb.co/jFEc4k (magically reappears) BUT!
https://ibb.co/fNDbx5
In different file explorer it shows correct filename and size. (Hope it helps~)