Joan,
Thanks a lot, I will check it soon.

Hi Joan,
Thanks for ur quick reply. I try to read the log.txt. And I guess the file name (named with simple chinese) cannot be read by kinovea,the log.txt related as the following:
    "4269 - DEBUG - [5] - VideoReaderFFMpeg - Switching decoding mode. OnDemand -> NotInitialized
     4284 - ERROR - [5] - VideoReaderFFMpeg - The file C:\Users\lenovo\Desktop\1920-1080 ????? ??4? ???vs????
     ELTA HD 1080P ??1_Trim.mp4 could not be openned. (Wrong path or not a video/image.)
     4284 - ERROR - [5] - VideoReaderFFMpeg - The file C:\Users\lenovo\Desktop\20181212 ?????????? ????
     VS???.2[0]_Trim.mp4 could not be openned. (Wrong path or not a video/image.)"

SO, I solved the above problems by changing the file name and file path from simple chinese into Engligsh characters. BUT, Why my classmate's pc (HP, win10) can open a video named with chinese characters?
Thanks in advance!
Ren

Hi there,
    Recently, I am always receiving  a warning message (Failure:unable to open the file: file not found or empty) from the kinovea 0.8.27 (64 bit) when I load videos from disks except C disk (where my operating system installed). And If I load a video more than 1 G, the warning message pops out even when the video loads from C disk. I have tried the editions released from the  website (kinovea?org), such as 0.8.27 (64 bit and 32 bit) and 0.8.15 (64 bit and 32 bit) , but the problems still cannot be solved .
    Many Thanks in advance!
Ren