Mick Hardy
Vegas 13 does not support the HEVC or H.265  format used by the GoPro 7 cameras.

Your options are:
  1. Set the camera to use H.264
  2. Update to Vegas 14 or higher
  3. Convert the footage using third party software such as Handbrake 

To change your GoPro, select "H.264 + HEVC" under Video Compression and then select a suitable resolution and frame rate such as 1080 at 25 fps.


Video Compression
Set the fle format for your videos. Choose HEVC (to reduce fle sizes) or
H.264 + HEVC (to use H.264 to maximize compatibility with older devices
while using HEVC for advanced settings).