Do you have an Android version of the player? Or a player that can play Android video files with gr suffix?
The early CSF file is in the format of CSF 1.0/2.0, which can be played by the teaching player. The latter format can be played with the ScenicPlayer, which is the follow-up product of the teaching player. This product can be compatible with all previous CSF version files, and can play all kinds of common audio and video media files at the same time. And for files with the same traffic, you will find that ScenicPlayer will render videos better!