I render my clips in mp4 format and often once I have rendered a clip I can not open it in the software. It appears on my timeline but when i put the cursor on it it not only does not show up on the preview window the whole thing freezes. I need to use some of these clips for my current project and I cant figure out how to do it. I would use the VF versions but I cant open 2 VF files at the same time. Please let me know how i can fix this.