In the past month I have had difficultly import MP4 and MOV footage into Premium.   I get an error stating there is no audio or video file.    I transcoded the video in Handbrake at Fast1080p30 and then the file imported.    I am no expert, but I am concern that the footage was shot at 24 frames not 30 frames.   Any, then I changed the file extension to MPG from MP4 and it imported fine.   I am not sure if there is a problem doing this, but it seemed to work.   
This is a strange issue and I thought people might find this helpful.  

are your files h265 thers a problem with h265 files wher the first 6 or so frames are broken and premier wont import it when playing it in vlc you can see blocks in the video you can also fix it using the convert option in vlc it only happens to some files like when you record 14 1 might have it have neet been able to force the problem yet and suport wont rly help at all all they say is send in the done ...

Why are you running the files through Handbrake first? Just try copying the file to you computer and import into Premier and see what happens.

Try using 1080P or 2.7k files from the P4P camera and see if you can import these without any issues, I find my PC struggles to import the 4k video files into Premier Pro due to the 100mbps file size but is fine with the 2.7 or 1080 as the are lower MBPS . My older PC is not up to the job but my iMAC can cope without issue with the 4k 100mbps files.

I am shoot in H264 and the files don't import into Premiere.   They did for months, but not now.   Handbrake was solution after trying a the typical fixes, clear catch, re-installing quicktime, etc.   Saving as mpg is much simpler than re-encoding.    I hope it is not a  problem to just change the extension on the files.

Hi, I shoot in  h.264 mode on my p3a they also imported just fine but when I got the P4P the 4k files would not on my pc but all were fine on the iMAC....its down to the bit rate the files are saved at, I also have a OSMO+ the 4k file from this also import on the PC, as they have a lower bit rate than the P4P so can cope and import fine. The file extension make no difference, no need to use anything else first to transcode the files - just use Premier Pro. All file types and sizes are imported fine on the iMAC.

I am not sure if this true.  First, I have no problems with P4P for the first 3 months I owned the drone.  Premiere handled it fine.   Also, I have not problems with 400mps clips in Premiere from my GH5.  I believe the issue is with an DJI or Premiere update.  Hopefully, it will be corrected soon.    I could roll back Premiere but I live in Maine and my internet is 1.5 mps on a good day.    It is not easy to deal with CC.
Best, Dean