...and you wouldn't, either. Adobe Media Encoder isn't a browser. I bet you'll find it's a user forum on the GoPro web page.
Cineform is a codec that you can download from GoPro although it's included in the latest version of Adobe's software.
What version of AE are you using (down to the last decimal)? What version of Premiere?
How did you render your video file? What were your original render settings from AE? What were the AE comp settings?
How did Premiere interpret the file once you imported it?