A situation like this indicates that the file is carrying some minor encoding errors. As the hardware specifications of the computer are a lot higher and more advanced than those of the MP710, such tiny encoding errors are negligible to the computer. For the MP710, however, its hardware is less tolerant to such encoding errors, resulting in playback failure or display errors.
You could download the "MP710 ToolBox" software to convert your file to another format. When converting, MP710 ToolBox will re-encode your file and correct its encoding errors in the process. After that, you will be able to play it on your MP710.
Step1: Import video files
Step2: Set video interval
Step3: Start converting
If you are still having trouble playing a video on the MP710 after converting it, this means that the encoding error is too big that not even converting the file would revert it back to its original state.